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Re:Userdir URLs like https://example.org/~username/ are dang... by rlpb on Tuesday April 07, 2020 @07:50PM (#22808739)
> All userdir URLs on one server run on the same host and thus are in the same origin. It has XSS by design.

The ship has now sailed, but I still think it's worth pointing out that it is Javascript's security model that is broken by design, that XSS vulnerabilities are the result, and the same origin policy is an incomplete workaround as illustrated by the article. This becomes clear when you consider that userdir URLs pre-date Javascript.

The public suffix list is yet another incomplete workaround for the security flaw in the same origin policy (that "same origin" isn't a concept that can be clearly defined).

The modern web stack is a security house of cards, as demonstrated.

Re:Userdir URLs like https://example.org/~username/ are dang... by vortico on Tuesday April 07, 2020 @07:58PM (#22808796)
Honestly I can't think of a much better system that can support a billion websites. What would you change/overhaul about the current system if you could ignore compatibility?
Re:Userdir URLs like https://example.org/~username/ are dang... by yoloClin on Wednesday April 08, 2020 @12:54AM (#22810186)
Firstly, I'd fix the damn spelling of the referer header instead of everybody putting up with it for close to 30 years.

I don't think it's that JavaScript and HTML are a bad choice, but there are some things that would have made life a lot easier if they were strongly enforced sooner, including secure cookies by default, SameSite=lax, removal of referer header and CSP - doing them sooner would have stopped bad developer practices while also removing a fair chunk of application security complexities, but at least we're moving towards a better world regarding those now.

I don't know if it'd be technically possible to implement, but additional characters to mark unsafe strings would have a huge impact on webapp security. Reflection of untrusted data at the moment generally relies on one of: HTML encoding, URL encoding or JavaScript escaping and escaping a safe way is highly context-dependent (I've seen an unescaped "\n" cause injection within JavaScript contexts). A way of effectively storing the level of trust a chunk of data has across multiple transports when marking untrusted data including within HTML/JS, SQL statements and interpreted languages like BASH or PHP - this would eliminate a bunch of vulnerabilities and would probably have mitigated a bunch of notable historic vulnerabilities and/or hacks.

Re:Userdir URLs like https://example.org/~username/ are dang... by squiggleblaz on Wednesday April 08, 2020 @04:46AM (#22811159)
> HTML encoding, URL encoding or JavaScript escaping and escaping a safe way is highly context-dependent (I've seen an unescaped "\n" cause injection within JavaScript contexts)

I have had a hard time convincing co-workers that if you have php generating sql generating (! yes!) html generating javascript, you need to escape the string for javascript since it's embedded in javascript. Then you need the string escaped for html since it's embedded in html. Then you need the string escaped for sql since it's embedded in sql. Only then can you chuck it into the middle of the string. It is better to not do such craziness; but once you've decided to do such craziness, you must do it properly. The similarities between js and mysql escaping are irrelevant; it must be escaped properly each time it is embedded in another language.

Re:Userdir URLs like https://example.org/~username/ are dang... by benibela on Wednesday April 08, 2020 @06:55AM (#22811771)
Escape characters are one of the most stupid things in the computing world.

The formats could be so simple: first the length of the data, then raw data of that length

Re:Userdir URLs like https://example.org/~username/ are dang... by cormacrelf on Wednesday April 08, 2020 @09:59AM (#22812991)
The better solution is allow control over what the terminating characters are. Rust raw strings allow N ‘#’ characters around them, like r”x”, r#”x”, r#####”x with “quotes””#####. So no escapes are ever needed, just increase the number of hashes to outstrip the maximum consecutive hashes appearing in the string after a quote character.
Re:Userdir URLs like https://example.org/~username/ are dang... by EamonnMR on Wednesday April 08, 2020 @08:10AM (#22812188)
But then we would never be able to treat text as a stream. All of your one pass algorithms would become two pass.
Re:Userdir URLs like https://example.org/~username/ are dang... by jl258 on Wednesday April 08, 2020 @09:05AM (#22812548)
I’m curious what you mean by this — why does coding for length prevent streaming? The receiving end can certainly treat the text as a stream still. Do you mean that the sender cannot “stream” if they are generating the contents on the fly? That seems trivial to solve - just break it up into chunks, assuming a little bit of buffering is OK.
[dead]
Re:Userdir URLs like https://example.org/~username/ are dang... by benibela on Wednesday April 08, 2020 @11:03AM (#22813561)
>How would it allow you to write a regex that matches a dot?

You could write

    1:.
>Or text in an XML element that includes an ampersand?

The point is to not use XML, because it has escape characters. You could replace it with ASN.1 BER

>Even for quotes contained in string literals it's a shitty solution because string literals are part of programming languages and having to count characters every time you change a String literal is just about the last thing you want in your language (and it would be horrible to read as well).

The IDE could update the length automatically

Re:Userdir URLs like https://example.org/~username/ are dang... by brazzy on Wednesday April 08, 2020 @04:41PM (#22816838)
> You could write 1:.

So separate wildcards and literals, each prepended by length? That would be far, far less readable than using escape sequences.

> The point is to not use XML, because it has escape characters. You could replace it with ASN.1 BER

Fair enough, but most people would consider that a solution worse than the problem.

> The IDE could update the length automatically

Making you completely dependent on an IDE to support whatever format you're editing, including nesting. You can't even read your code now without an IDE. Making up some kind of DSL on the fly? Start counting string lengths again.

Sorry, but no. Escape sequences are bad, this would so much worse.

Re:Userdir URLs like https://example.org/~username/ are dang... by benibela on Thursday April 09, 2020 @01:26PM (#22824953)
>So separate wildcards and literals, each prepended by length? That would be far, far less readable than using escape sequences.

Wildcards do not need a prefix, when they always are a single character.

Here is a ordinary regex for a path:

    C:\\foo\\bar\\.*\.txt
And here the regex in C:

    "C:\\\\foo\\\\bar\\\\.*\\.txt"

But with lengths in a hypothetical syntax:

    11:C:\foo\bar\.*4:.txt


    22:11:C:\foo\bar\.*4:.txt
That is quite readable

> You can't even read your code now without an IDE. Making up some kind of DSL on the fly? Start counting string lengths again.

I like binary formats. The lengths are easy to see in a hex editor. 16 bytes in each line or something

You always depend on an IDE to decode the file. You could not read an UTF-8 file, if it would not decode the UTF-8 characters and show individual bytes. Or read ASCII if it were showing individual bits.

Re:Userdir URLs like https://example.org/~username/ are dang... by yoloClin on Wednesday April 08, 2020 @05:48PM (#22817559)
Irrespective of who's right or wrong it's pretty unnecessary to call each other names just because you don't agree, particularly when the question is theoretical and has almost no real world impact.
Re:Userdir URLs like https://example.org/~username/ are dang... by jl258 on Wednesday April 08, 2020 @09:02AM (#22812524)
Commenter above, correct me if I’m misinterpreting, but — I imagine they meant for when programs talk to other programs. Regexes and string literals are written by humans; it would be easy for the compiler/program to calculate the length for you.
Re:Userdir URLs like https://example.org/~username/ are dang... by jcranmer on Wednesday April 08, 2020 @09:39AM (#22812832)
The general solution is parametric construction. When we're building SQL queries, regular expression matchers, HTML files, etc., we're actually attempting to build a richer data structure but representing it as a flat string. Instead of concatenating strings, we can turn our original string into one where some leaf nodes are placeholders for future literal entities, which can be substituted for their actual values without fear of potential metacharacters that could be misinterpreted.

While the solution may be fairly clear, not everyone provides easy interfaces for parametric construction--regular expression engines being the one where the lack is the most distressing for me (although this is less because I need to substitute in user-generated strings and more because I want to combine smaller regexes into larger ones to make the regex easier to follow).

Re:Userdir URLs like https://example.org/~username/ are dang... by brazzy on Wednesday April 08, 2020 @09:15AM (#22812621)
Which would, again, only help with delimiters, but not with other characters that have special meaning but also need to be used literally.
Re:Userdir URLs like https://example.org/~username/ are dang... by solarengineer on Wednesday April 08, 2020 @09:08AM (#22812574)
From https://en.wikipedia.org/wiki/HTTP_referer

“ The misspelling of referrer originated in the original proposal by computer scientist Phillip Hallam-Baker to incorporate the field into the HTTP specification.[4] The misspelling was set in stone by the time of its incorporation into the Request for Comments standards document RFC 1945; document co-author Roy Fielding has remarked that neither "referrer" nor the misspelling "referer" were recognized by the standard Unix spell checker of the period.[5] "Referer" has since become a widely used spelling in the industry when discussing HTTP referrers; usage of the misspelling is not universal, though, as the correct spelling "referrer" is used in some web specifications such as the Document Object Model.”

Re:Userdir URLs like https://example.org/~username/ are dang... by cmiles74 on Wednesday April 08, 2020 @09:18AM (#22812647)
I have to disagree that the misspelling "referer" has "become a widely used spelling" even with the qualification "in the industry when discussing the HTTP referrers", a qualification too specific to be useful, in my opinion. In my experience getting the spelling wrong leads to much frustration and annoyance to this day.
Re:Userdir URLs like https://example.org/~username/ are dang... by twic on Wednesday April 08, 2020 @02:57AM (#22810630)
For the same-origin problem, the web server could return an Origin header which defines the origin. So the server on example.org could serve https://example.org/~username for anything in that account. The defined origin would have to be under the scheme, domain, and port served by the server, of course.
Re:Userdir URLs like https://example.org/~username/ are dang... by dwb on Wednesday April 08, 2020 @06:16AM (#22811612)
This is not true; a URL with anything past the port is not a valid "origin"

https://tools.ietf.org/html/rfc6454#section-7

Re:Userdir URLs like https://example.org/~username/ are dang... by joosters on Wednesday April 08, 2020 @08:03AM (#22812139)
I think their point was that the concept could be expanded as per their suggestion, as a simple way to fix the security issues.

Having the server send a 'this is my site base' header would be helpful even without having path support. At the moment, browsers need to magically know about all multi-level domains, like example.co.uk, so that they don't lump together all *.co.uk domains as the same site.

Re:Userdir URLs like https://example.org/~username/ are dang... by twic on Wednesday April 08, 2020 @09:07AM (#22812565)
Yes, this was my meaning - apologies if i wasn't clear.
Re:Userdir URLs like https://example.org/~username/ are dang... by couchand on Wednesday April 08, 2020 @10:06AM (#22813044)
This is brilliant and simple and backwards-compatible. Well done. If I knew anything about the standards process I would write an RFC for it today.
Re:Userdir URLs like https://example.org/~username/ are dang... by andy_ppp on Tuesday April 07, 2020 @10:00PM (#22809397)
I still think it's a miracle that the browser was the solution to the client-server problem x-windows was trying to solve all along.

How we ended up with billions of people able to interact with an app that we can all build at home seems insane...

Re:Userdir URLs like https://example.org/~username/ are dang... by kick on Tuesday April 07, 2020 @10:30PM (#22809506)
I still think it's a miracle that the browser was the solution to the client-server problem x-windows was trying to solve all along.

X was the solution to the problem MIT had, and as such, the problem X was trying to solve. It worked very, very well for what it was trying to solve.

How we ended up with billions of people able to interact with an app that we can all build at home seems insane...

Java. Java did this. On billions of devices! Everywhere from your smart card to the mainframe. Before Java, Dis! Before Dis, Forth! Good luck running a web browser plus your application on a smart card, or even (decently) on an underpowered netbook.

Re:Userdir URLs like https://example.org/~username/ are dang... by owl57 on Tuesday April 07, 2020 @11:02PM (#22809650)
Good luck running a web browser plus your application on a smart card, or even (decently) on an underpowered netbook.

Sufficiently young people probably suspect these were called netbooks as some joke. They run Emacs just fine and without constantly swapping, but a web browser?

Re:Userdir URLs like https://example.org/~username/ are dang... by hedora on Tuesday April 07, 2020 @11:32PM (#22809796)
They’re fine little web browsers if you manage to enable web browser acceleration for the integrated intel video card.

If not, they can’t even run JavaScript ads, because apparently ads like to refresh the screen with a static image at 60fps. Software rasterizers can’t keep up with that (even on 32 core, >200W TDP xeons, from what I’ve seen...)

The web really sucks at everything other than network effects.

Re:Userdir URLs like https://example.org/~username/ are dang... by otabdeveloper4 on Wednesday April 08, 2020 @03:29AM (#22810787)
> They’re fine little web browsers if you manage to enable web browser acceleration for the integrated intel video card.

Hardware acceleration makes things slower, not faster.

> Software rasterizers can’t keep up with that (even on 32 core, >200W TDP xeons, from what I’ve seen...)

You're nuts. Software rasterizers keep up with DOS games just fine, even on an old 386.

It's the fact that they're trying to use Javascript and other garbage-collected or object-oriented languages to code these rasterizers.

Re:Userdir URLs like https://example.org/~username/ are dang... by lazyier on Tuesday April 07, 2020 @11:19PM (#22809731)
If X-windows wasn't complete garbage at actually providing remote applications then it may have had a chance.
Re:Userdir URLs like https://example.org/~username/ are dang... by klodolph on Tuesday April 07, 2020 @11:47PM (#22809851)
Being complete garbage didn’t stop JavaScript either :/

At least JS had the excuse of being designed and implemented by a single developer in three weeks. X Windows was part of Project Athena, a $50 million project from MIT, DEC, and IBM with a five-year schedule.

Re:Userdir URLs like https://example.org/~username/ are dang... by kick on Wednesday April 08, 2020 @12:02AM (#22809920)
X worked great for what it was aiming to do. It's not even bad for really remote applications. It works really well, just don't use a dozen layers of poorly-designed abstraction. Write something with xcb or xlib, and you'll get instantaneous response from the other side of the planet.

Here's a nice little article from 1989 telling just how great it was for the time:

https://simson.net/clips/1989/1989.TechRev.Athena.pdf

Re:Userdir URLs like https://example.org/~username/ are dang... by klodolph on Wednesday April 08, 2020 @02:15AM (#22810483)
Eh, that’s a nice fluff piece but doesn’t match my understanding or experiences working with X. Once X had more widespread adoption in the 1990s you started to see a lot more hate.

The layers of abstraction are there because X is such a godawful piece of shit. Sure, your application will be fast if you only use XCB or Xlib (and XCB is just a modern replacement for Xlib, made because of how deeply flawed Xlib is, and it can’t even fully replace Xlib). But few people are willing to put in the blood, sweat, and code to write something that is pure X.

So if X worked great for what it was aiming to do, it was aiming to do the wrong thing.

Re:Userdir URLs like https://example.org/~username/ are dang... by kick on Wednesday April 08, 2020 @10:59AM (#22813518)
X was hated when it got widespread adoption because people began using it for things it wasn't intended for. X was aiming to do the right thing.

Sure, if you're using it to connect to a box in Canada over a satellite connection in Johannesburg during 1995 with countless abstractions, you're going to have a horrible time. Use the right tool for the job.

Re:Userdir URLs like https://example.org/~username/ are dang... by DonHopkins on Wednesday April 08, 2020 @11:22AM (#22813702)
X-Windows IS a dozen layers of poorly-designed abstraction, itself. To the core. Most of which nobody even uses any more. But is still required to be there. And yes, it is extremely bad for remote applications.

The X-Windows Disaster

https://medium.com/@donhopkins/the-x-windows-disaster-128d39...

>X: The First Fully Modular Software Disaster

https://news.ycombinator.com/item?id=17056516

John Steinhart wrote XTool, a nice snappy reimplementation of X11 on top of SunView! ;)

https://web.archive.org/web/20171008204348/https://minnie.tu...

X and NeWS History

https://news.ycombinator.com/item?id=15325226

Jon Steinhart wrote:

>XTool was very small and fast compared to the X sample server because I wrote the server from scratch. I think that I'm the only person to write an X server outside of the X Consortium. One of the things that I learned by doing it was that the X Consortium folks were wrong when they said that the documentation was the standard, not the sample server. There were significant differences between the two.

>The only really worthwhile thing about X was the distributed extension registration mechanism. All of the input, graphics and other crap should be moved to extension #1. That way, it won't be mandatory in conforming implementations once that stuff was obsolete. As you probably know, that's where we are today; nobody uses that stuff but it's like the corner of an Intel chip that implements the original instruction set. As an aside, I upset many when working on OpenDoc for Apple and saying the same thing there.

>The atom/property mechanism allows clients to allocate memory in the server that can never be freed. Some way to free memory needs to be added.

>The bit encodings should be part of a separate language binding, not part of the functional description.

>Had he done some real design work and looked at what others were doing he might have realized that at its core, X was a distributed database system in which operations on some of the databases have visual side-effects. I forget the exact number, but X includes around 20 different databases: atoms, properties, contexts, selections, keymaps, etc. each with their own set of API calls. As a result, the X API is wide and shallow like the Mac, and full of interesting race conditions to boot. The whole thing could have been done with less than a dozen API calls.

Re:Userdir URLs like https://example.org/~username/ are dang... by DonHopkins on Wednesday April 08, 2020 @06:51AM (#22811755)
Thank you for saying "X-Windows". ;)

Recommendation: People who like saying "X-Windows" also enjoy saying "Project Anathema".

Re:Userdir URLs like https://example.org/~username/ are dang... by asveikau on Wednesday April 08, 2020 @12:43AM (#22810134)
I like it better than VNC or RDP, especially on a fast network.

Those others I think get it wrong with their "whole desktop" sharing. The experience of having X clients streamed as they are launched and the local WM gets to manage decorations - I like that model a lot more, for say the scenario where I ssh into a machine and launch a GUI program.

RDP is much faster than X. It had the benefit of being designed later I guess.

VNC usually feels laggier than X to me somehow. As if there is a cursor sync issue.

These are just my observations as a user.

Re:Userdir URLs like https://example.org/~username/ are dang... by cryptonector on Wednesday April 08, 2020 @03:02AM (#22810655)
It's been said that NeWS could have been the web.
Re:Userdir URLs like https://example.org/~username/ are dang... by jlgaddis on Thursday April 09, 2020 @11:52AM (#22823718)
Pretty much all modern web servers support per-user virtual hosts using wildcards that allow for URLs like http://username.users.example.org/ (instead of http://users.example.org/~username/ when using mod_userdir).

Unless I'm missing something, it seems that this would eliminate most of the issues raised in the article by using a separate subdomain for each user/site.

Using lighttpd, you can do this with this very simple configuration [0]:

  $HTTP["host"] =~ "users\.example\.org" {
      evhost.path-pattern = "/home/%4/public_html/" 
  }
Add a "wildcard" record for "*.users.example.org" pointing to the proper host to your DNS zone and you're all set.

---

[0]: https://redmine.lighttpd.net/projects/lighttpd/wiki/Docs_Mod...

Re:Userdir URLs like https://example.org/~username/ are dang... by hamilyon2 on Wednesday April 08, 2020 @06:52AM (#22811757)
If website is non-trivial, i. e. user have to login to it, I would encrypt all urls with client-specific key. So that it is non-sharable and unforgable
Re:Userdir URLs like https://example.org/~username/ are dang... by ergothus on Wednesday April 08, 2020 @05:18PM (#22817279)
Isnt that contrary to the point of urls?
Re:Userdir URLs like https://example.org/~username/ are dang... by chx on Wednesday April 08, 2020 @02:49AM (#22810603)
> What would you change/overhaul about the current system if you could ignore compatibility?

Say, you have some endpoints which can do a public key crypto signature verification. Part of the cookie data is such an endpoint URL. If a script loaded into a page wants to read a cookie, the endpoint defined by the cookie checks the signature of the script and the browser accordingly allows or not access to the cookie. As you'd sign the scripts during deployment, the private key is not even on the public servers.

For performance reasons probably wouldn't send the entire script just a hash of it so it's like GET https://example.com/check?hash=1234567890&signature=abcdef and there's a simple 200 or 403 response. You could make the API such that you can bundle multiple hashes and signatures together so the entire overhead over the network is a single request for every endpoint. If you want to be fancy, you can have a response body for the 403 response which tells the browser something like "this hash is of an outdated version, plz ignore cache and load a new one".

Re:Userdir URLs like https://example.org/~username/ are dang... by yoloClin on Wednesday April 08, 2020 @03:26AM (#22810767)
Secrets stored in cookies really shouldn't be accessible, the Set-Cookie HttpOnly flag should stop all JS access to a cookie. The HttpOnly flag still submits a cookie when you do an ajax GET/POST, but you cannot access the cookie via document.cookie or similar.

There's also external resource integrity checks which prevent modification of third party resources without breaking the local site. jQuery CDN code snippets do this by default: https://code.jquery.com/ .

You can't trust one script to access a cookie without trusting all scripts to access the same cookie though - while I can see some merit to the idea when it comes to hiding secrets from XSS/untrusted code, I'd say that in most (99.9%) situations effort would be better spent actually implementing CSP and good data sanitation rather than caring about implementing JavaScript level trust models.

Re:Userdir URLs like https://example.org/~username/ are dang... by cryptonector on Wednesday April 08, 2020 @03:00AM (#22810643)
Yes, the server signing its scripts would do it, provided the server doesn't blindly sign attacker-submitted code. Some servers might...
Re:Userdir URLs like https://example.org/~username/ are dang... by 6510 on Wednesday April 08, 2020 @01:52AM (#22810401)
Make applications into a single file that can pull aditional xml and json data, images and video by appending the session key. If the application desires to do something other than display the data the user must give permission. No more checking if the json has a key but map it to a dom element and make that [and all its parents] unreadable.

(Keep all the legacy crap for when this is not enough)

Re:Userdir URLs like https://example.org/~username/ are dang... by pwdisswordfish2 on Tuesday April 07, 2020 @11:09PM (#22809681)
If you honestly can’t think of one, that only demonstrates your lack of imagination.

I, for one, would imagine something based on a DNS TXT records that either directly contain or point to a URL describing some kind of security domain policy: whether and which subdomains and subdirectories should be considered separate, isolated security domains, with pattern matching, of course. Or maybe put it under /.well-known/ instead of DNS. At the very least, this would solve the unregistration problem of PSL (i.e. when an entry becomes stale, you will not immediately know it, and old versions of your product will still treat it as present).

Re:Userdir URLs like https://example.org/~username/ are dang... by wutwutwutwut on Wednesday April 08, 2020 @12:22AM (#22810046)
Using DNS TXT to solve a XSS issue? That's clearly another card added to the house.
Re:Userdir URLs like https://example.org/~username/ are dang... by yoloClin on Wednesday April 08, 2020 @03:27AM (#22810776)
IMO, using DNS for anything other than hostname lookups is a complete hack. I'm looking at you, SPF.
Re:Userdir URLs like https://example.org/~username/ are dang... by pbhjpbhj on Wednesday April 08, 2020 @08:04AM (#22812143)
It's a reasonable hack though. Where else do you put "how to interact with this domain" data, you can't serve that data (eg via http) because clients need to already know how to interact with that domain before they interact with that domain?

How would you do it?

Re:Userdir URLs like https://example.org/~username/ are dang... by yoloClin on Wednesday April 08, 2020 @05:03PM (#22817108)
Transport encryption with PKI.
Re:Userdir URLs like https://example.org/~username/ are dang... by hn_throwaway_99 on Tuesday April 07, 2020 @11:31PM (#22809784)
> The modern web stack is a security house of cards, as demonstrated.

Perhaps, but I feel like major recent changes are fixing most of these vulnerabilities:

1. Content Security Policy locks down most of the vulnerabilities that result from something on a page being able to contact something from a different origin. Of course, it's not set by default and these days requires a lot of trial and error to figure out the "right" way to set it, but it solves a lot of issues.

2. On the cookie front, the recent changes to the default SameSite behavior also pretty much end CSRF bugs.

Re:Userdir URLs like https://example.org/~username/ are dang... by objectified on Wednesday April 08, 2020 @06:04AM (#22811567)
1. Like you already hinted at, it is really difficult to get right, and I hardly experience any larger website (with multiple teams working on it) that implement it effectively. So while it's great in theory, I'm not sure if it's accessible enough (and therefore effective enough) for most of the world.

2. I'm assuming you're talking about Chrome's SameSite value; it's worth to note that this has been rolled back a short while ago because of compatibility issues in larger government organizations having to be accessible especially now with COVID-19. More info here: https://9to5google.com/2020/04/03/chrome-rolls-back-cookie/

Re:Userdir URLs like https://example.org/~username/ are dang... by hn_throwaway_99 on Wednesday April 08, 2020 @02:32PM (#22815603)
1. It's not really hard to get right, it just takes a lot of trial and error. I.e. you essentially start with the default-src as 'self', and then create exceptions to other resources as you need them. You use the report-uri/report-to endpoints to get reports if either (a) you've neglected to open up a resource you need, or (b) you DO have a vulnerability that someone is trying to take advantage of. While this may sound like a bit of a pain, e.g. if you have multiple teams working on a website that all need to access their set of 3rd party endpoints, this pain is required for good security: it forces you to be explicit about the 3rd party endpoints you allow, instead of the browser just allowing any endpoint for things like script tags, imgs, etc. which is the default now.

2. Note what Chrome is rolling back is the SameSite default change. SameSite has existed for quite some time now, in all browsers, it's just that the default is currently 'None' in Chrome but is changing to 'Lax'. So you can still take advantage of this now, it's just Chrome is delaying changing the default so that it doesn't break sites who aren't prepared for the default change.

So my point is the tools currently available really tighten up the sandbox guarantees of the browser, and make it no more difficult than necessary to build a secure site.

Re:Userdir URLs like https://example.org/~username/ are dang... by pdimitar on Wednesday April 08, 2020 @01:26AM (#22810310)
Would you provide links elaborating your both points? I haven't kept myself up to date with the web's security and I'm curious how those two problems were solved.
Re:Userdir URLs like https://example.org/~username/ are dang... by vbezhenar on Tuesday April 07, 2020 @08:56PM (#22809099)
You can specify Path attribute for cookie and it will only be sent to URls with this prefix. I'm not completely sure, but I think that it should solve those security flaws.
Re:Userdir URLs like https://example.org/~username/ are dang... by justinsteven on Tuesday April 07, 2020 @10:53PM (#22809617)
It would not. It would stop the cookie from being sent to things outside of the path specified, but the Same Origin Policy is about, among other things, gaining read-access to the responses of fetch/XMLHttpRequest/AJAX requests.

If there is a cookie set for the path '/secret' and I can host content at '/attacker', then some of my JavaScript under /attacker could do a fetch request to /secret/something. This fetch request would carry the cookie for /secret, and the response would be readable by my JavaScript (due to Same Origin Policy). I could read the response, extract sensitive content, or even extract CSRF tokens to allow me to do state-changing CSRF-protected things under /secret

Re:Userdir URLs like https://example.org/~username/ are dang... by vbezhenar on Tuesday April 07, 2020 @11:22PM (#22809752)
What about setting Cookie with Path and SameSite=LAX? I would expect it to prevent sending cookies in that request, although I did not test it.
Re:Userdir URLs like https://example.org/~username/ are dang... by justinsteven on Wednesday April 08, 2020 @12:17AM (#22810020)
I tested with SameSite being Lax and Strict. Neither block the attack in Chrome. My reading of the SameSite spec indicates that it doesn't take cookie path into account.
Re:Userdir URLs like https://example.org/~username/ are dang... by k1t on Tuesday April 07, 2020 @09:35PM (#22809289)
If you own example.com and want to have cookies accessible in the root (e.g. example.com/login.html) then you can't prevent example.com/users/~evildoer from accessing them.
Re:Userdir URLs like https://example.org/~username/ are dang... by squiggleblaz on Wednesday April 08, 2020 @05:11AM (#22811281)
Don't we have equivalent problems with evildoer.example.com trying to get and set example.com cookies? Hence why Google and Github and other major sites use separate domain for user hosted content vs first party content.

Cookies are a terrible security model in general.

Re:Userdir URLs like https://example.org/~username/ are dang... by budgi4 on Tuesday April 07, 2020 @09:48PM (#22809343)
No, but you could redirect your root requests to example.com/home and serve from there with relevant cookies restricted to the /home path.
Re:Userdir URLs like https://example.org/~username/ are dang... by danShumway on Tuesday April 07, 2020 @09:09PM (#22809167)
> The public suffix list is yet another incomplete workaround for the security flaw in the same origin policy (that "same origin" isn't a concept that can be clearly defined).

Origins are very clearly and rigorously defined[0].

It's just that people have a tendency to group multiple applications/users on the same origin. Now, would it be nice to optionally allow servers to be more restrictive? Sure. There are a few privacy implications there, but I could easily see someone making a case for that. I think I'd possibly support an HTML directive that allowed you to have a stricter same-origin policy (ie, restrict to current URL, or restrict to parent path).

At the same time, setting up subdomains that point to static directories is really stinking easy. And I am skeptical that any web host that refuses to use subdomains is going to care enough about security to opt-in to an even more aggressive scheme. A website that is hosting 3rd-party sites via userdirs is a website that will ignore or circumvent any security model you propose.

> The public suffix list is yet another incomplete workaround for the security flaw in the same origin policy

No, the opposite. The public suffix list is a workaround for the flawed security model of cookies. In your focus on Javascript, you are missing the much bigger problem. See below:

> there is however still a caveat with this: Unfortunately the same origin policy does not apply to all web technologies and particularly it does not apply to Cookies.

The same-origin policy is (overall) fine, the problem is that the old web security model didn't have it. So we are trying to retroactively build a modern security model based on strict, on-by-default isolation on top of a flawed security model that assumed every single domain would be owned by a single entity. Cookie "contexts" are a lot broader than modern definitions of "origins". They can be inherited from parent domains, they can be trivially shared across domains without user consent. And they also aren't by-default isolated across userdirs.

This has all turned out to be, broadly, a bad idea. While I don't think the same-origin policy is perfect, it's pretty obviously better than what we were using before. This is why you're seeing movement from the Chrome team to turn on SameSite isolation by default for cookies. Because we look back at the original web security model and realize that opt-in SameSite and randomized form-submit tokens for security were always a mistake.

All of this is dancing around that you mention that userdir URLs pre-date Javascript. To be clear, userdir URLs were inherently insecure from the moment they were conceived. You should not have been hosting websites this way, even before Javascript existed.

To the extent that people got away with this kind of thing before Javascript, it was only because userdir websites were so ridiculously limited that they often didn't have any serverside capabilities to respond to form submissions, or to run any kind of logic at all. To the extent that people weren't widely phished on userdir-hosted sites by fake forms with hidden fields that sent logic to parent origins or to other sites they were already logged into, it's only because the web was so young and so tiny that we were able to get away with bad security -- the same way that in a rural area I can get away with leaving my garage unlocked.

I'm not exactly happy with every decision modern browsers are making about the direction of web security, but I would challenge anyone to look at the history of CSRF mitigations and then say that the same-origin policy is not a universally better security model for Javascript to adopt.

[0]: https://developer.mozilla.org/en-US/docs/Web/Security/Same-o...

Re:Userdir URLs like https://example.org/~username/ are dang... by Spivak on Tuesday April 07, 2020 @11:10PM (#22809685)
I think you’re ignoring the fact that the browser security model is based on a flawed definition of an origin that prohibits something that has very little reason not to work. Userdir sites weren’t/aren’t limited at all. If you dropped a php file into your directory it would run.

domain.suffix/full/path should have been the definition of an origin because people were literally using it as such. The default config of the most popular web server at the time was doing it. People hosted entirely different sites in subdirectories because it was really easy to just create a directory. TV ads directed people to www.blahblah/sitename.

The real definition of origins is clever since the path before the domain defines an origin path and everything after is owned by that origin. Neat and tidy for sure but broke userspace so to speak.

Re:Userdir URLs like https://example.org/~username/ are dang... by danShumway on Wednesday April 08, 2020 @12:40AM (#22810127)
> but broke userspace

But that's never how userspace was ever designed to work during the web's history. Hosting sites this way, especially commercial ones, was always insecure because of the way cookies were designed from day one.

Same-site policies broke userspace in the same sense that Wayland is breaking X11 userspace by making it so applications can't just send keypresses to each other. Userspace was already broken, it was an insecure mess -- it's just that we recognize it now. If you were running a userdir site that supported PHP, you probably should not have been doing that.

I'm glad nothing got hacked for the people doing it, but I used to leave my bike unchained at the library growing up, and it didn't get stolen either -- didn't make it secure. I believe you that there was a time when companies advertised on TV using userdirs, because I know there was a time when Facebook only used SSL for its login screen and when Twitter forced users to enable SSM account recovery. Companies do insecure crap sometimes :)

If you don't care about same-site security, then nothing's broken -- the vulnerabilities you're exposed to now in a post-Javascript world for userdir sites are the same ones you were exposed to back then. It's just users today are more likely to actively exploit them.

Re:Userdir URLs like https://example.org/~username/ are dang... by Spivak on Wednesday April 08, 2020 @12:55AM (#22810192)
I'm in no way saying that it wasn't a broken insecure mess and needed fixing -- just that the fix that actually happened broke some already established ways of organizing websites. Any website that relied on that doing naughty things with cookies that crossed logical boundaries they weren't supposed to -- sure -- makes total sense to break them. But having one site at mysite.com/a and another at mysite.com/b is a perfectly valid use cause and ought to have had a path to being secure instead of being fundamentally insecure which is what we have now.

Like doesn't it seem a little silly that you can't make a.mysite.com and mysite.com/a behave the same way?

Re:Userdir URLs like https://example.org/~username/ are dang... by danShumway on Wednesday April 08, 2020 @01:26AM (#22810309)
Maybe?

The current system is mostly consistent with the way that SSL UX works, it's consistent with the way modern browsers display URLs. From an engineering perspective it's silly, but we're also thinking about ways to easily get across to users 'who owns the thing you're looking at'. It's also nice to have a rigid boundary somewhere, because it allows us to turn on isolation by default; the same-origin policy isn't something programmers have to remember to opt into. So there's UX questions like, "by default should cookies only resolve to a single URL, and programmers have to whitelist subpaths? Would any of the web operators doing this today care enough to actually implement an optional security feature?"

All that being said, I'm broadly sympathetic to an argument that same-origin policies didn't go far enough. I think you can make a very reasonable argument that origins are pretty arbitrary, and that the problems I list above are solvable, and that regardless of the original design we should adapt to what users want to do. That's a fine position to take.

I'm not sympathetic to the top-level argument I was originally responding to; that Javascript has fundamentally made things worse, or that the same-origin policy is a house of cards waiting to collapse, or that that browser policies like same-origin and SameSite aren't basic security improvements over what the web used to be before JS. The truth is, while imperfect, web browser security is still (broadly) very good. I question if there is any user-accessible native platform that comes even close to the web in having decent process/network/data isolation. There is no house of cards collapsing, in reality most native platforms like phones are largely playing catch-up to implement the same sandboxing features that the web has had for nearly a decade.

I get that's not the argument you're making, you're looking at this through the lens of, "should this be supported?". And again, that's reasonable. I do want to re-emphasize though; if you still want to host using userdirs, no browser capabilities have been removed, and nothing is any more insecure than it used to be. You're using the word 'broke', I'm not sure I get what you mean by that. There was an insecure thing people were doing, and they can still do it today with the same consequences. Nothing has fundamentally changed.

Re:Userdir URLs like https://example.org/~username/ are dang... by barnabee on Wednesday April 08, 2020 @03:03AM (#22810658)
> by default should cookies only resolve to a single URL, and programmers have to whitelist subpaths?

That sounds sensible! I always wondered why the origin and cookie scope isn’t limited to the full URL of the resource that set it and only explicitly extendable by something like <link rel=“same-origin”...>

Basically make every URL it’s own security and permissions sandbox but allow the programmer some latitude to extend it (and probably the administrator of parent directories/domains some capability to restrict how far up/across the tree a URL can reach, with the default perhaps being to allow only within same domain and path.)

Re:Userdir URLs like https://example.org/~username/ are dang... by crtlaltdel on Tuesday April 07, 2020 @10:45PM (#22809570)
noticing a lot of comments about how this is a “javascript” problem. i just want to clarify whether or not people are asserting this is a _language design_ issue, or an implementation of the runtime specifically within the context of web browsers and web servers?

is this a js problem?

Re:Userdir URLs like https://example.org/~username/ are dang... by danShumway on Tuesday April 07, 2020 @10:57PM (#22809629)
No, it has very little if anything to do with Javascript. My charitable reading is that people are using JS as a colloquial term to refer to the Web as a platform in general.

To the extent that it's a browser problem at all, it's a problem with how browsers as a platform handle HTTP requests and site-isolation, which is a security system that predates Javascript.

Re:Userdir URLs like https://example.org/~username/ are dang... by yoloClin on Wednesday April 08, 2020 @03:50AM (#22810871)
The issue is an injection attack. The ability to insert either unsanitised HTML data or data reflected inside the context of a JavaScript code block which results in JavaScript execution (by <script> tags, being able to specify data in DOM element events such as onClick or onError, or being able to specify code in onClick/onError events). I don't consider this a flaw in JavaScript itself, rather how JavaScript is harnessed from HTML.

Once JavaScript execution is obtained* it's possible to inject a JavaScript keylogger and/or rewrite the DOM to request authentication details from the victim (resulting in credential compromise). Alternatively, it's possible use AJAX to perform GET/POST requests to the same domain, routed through the victims browser which includes all cookies etc - effectively this is a time-boxed account compromise (CSRF controls do not apply when requests are executed from the local domain).

It's also possible to coerce a browser into triggering the exploit in a hidden iframe on a completely different page (eg you browse to evil.com, there's a hidden iframe which exploits an XSS vulnerability on facebook.com, compromising your facebook account if your currently logged into facebook on the exploited browser). I'm pretty sure samesite=strict only fix this if the XSS vector on facebook.com requires the user to be authenticated prior to exploitation, similarly, samesite=lax will not prevent attacks which require authenticated POST primitives.

*I'm a pentester, so that's sometimes my job, I don't break laws.

Re:Userdir URLs like https://example.org/~username/ are dang... by adt2bt on Tuesday April 07, 2020 @10:49PM (#22809592)
IMO, yes and no. The language design isn’t to blame. The libraries and runtime that are colloquially known as JS are. It’s hard to separate the two in discussion so the term js is a bit overloaded.
Re:Userdir URLs like https://example.org/~username/ are dang... by temporallobe on Tuesday April 07, 2020 @11:36PM (#22809805)
Thanks for pointing this out because I was just going to say the same thing. It’s most definitely not a Javascript problem, as Javascript is just a language, and nothing about the language design is inherently insecure. The problems are with the implementation of the browsers’ security mechanisms, some of which are indeed controlled via JS.
Re:Userdir URLs like https://example.org/~username/ are dang... by LunaSea on Wednesday April 08, 2020 @04:20AM (#22811025)
This is demonstrably false.

HTML is based on XML and even if you remove JavaScript, you could still create XML tags and attributes that lead to malicious behaviour and information leaks.

Want to guess which vulnerability jumped from not being in the OWASP top 10 to being in the 4th place? XML External Entities (XXE).

Re:Userdir URLs like https://example.org/~username/ are dang... by hhas01 on Wednesday April 08, 2020 @06:10AM (#22811590)
HTML is based on SGML. XML is a subset of SGML. XHTML is HTML converted to valid XML. IANAE, but I suspect most problems originate with SGML, which was designed for flexibility and extensibility rather than security. That’s compounded by the sprawling complexities of both HTML and XML that easily masks weaknesses and holes and makes implementation very hard to verify. Road to Hell, etc.