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Posted by negura 8 hours ago

Actively exploited sandbox RCE in all Chromium versions(nvd.nist.gov)
370 points | 211 commentspage 2
pertique 3 hours ago|
Not to downplay the severity (patch your browsers!), but there have been 5-10 actively-exploited V8 type confusion vulnerabilities in the last year. I'd be curious if this one blew up because it was the only one that was posted, or if it barely crossed some line in the collective consciousness this time around.
basilikum 6 hours ago||
For what is this exploited in the wild when it doesn't include a sandbox escape?

Is this chained with n-days?

pizlonator 4 hours ago||
There's a risk that someone had been sitting on a sandbox escape that assumed having RCE inside the sandbox first, and so they'd been waiting for an RCE exactly like this one.

Those folks would not be disclosing their sandbox escape unless they were good guys.

(Posted with a memory safe WebKit, Fil-C FTW)

pizdocalmin 3 hours ago||
[flagged]
sebstefan 4 hours ago|||
If it's in the CISA known exploited vulnerabilities catalog, tell me if I'm wrong but I assume people don't go around exploiting million dollar 0-days in public just to fuck around safely in a chrome sandbox.

So maybe we're going to see another CVE for the sandbox escape soon?

daveguy 4 hours ago||
Crypto mining would be one application. But also, combined with a sandbox escape would make it particularly devastating. Usually full control of a device takes at least two exploits given the layers of security present in OS and browser environments.
johnnyApplePRNG 5 hours ago||
NIST probably had this one filed and ready to announce years ago

like those news agencies have obituaries of famous old people pre-written

edoceo 5 hours ago|
I know a regular old geezer who's written his own obituary. Publish this when I die.

I bet famous people have their people write one to distribute immediately.

Also, writing those for your family sucks, easier to do it when they are alive and can tell some key stories.

TZubiri 6 hours ago||
Why is this 8.8?

It's because User Interaction is Required. CVSS 10 would be the case where everyone can be exploited without interaction.

Interestingly the 8.8 is more alert-worthy than the 9.8 and 10 cvss, because there is a need to be alerted of the current security risk, whereas with a cvss 2 vuln, there is nothing to be done by users, only admins.

roschdal 2 hours ago||
[flagged]
turpentine 1 hour ago|
What does your vibe-coded-in-C browser do to mitigate this kind of exploit?
Animats 4 hours ago||
Chromium, or just Chrome?
Terr_ 7 hours ago||
As somebody who prefers to browse with JS off whenever possible, there's something absurd about the balance everyone takes for granted between (A) your personal safety against a devastating hack by malicious code and (B) surveillance advertising.

"Sorry, but to enter this shop you need to take one of the used syringes from that pile some dude delivers every day and poke yourself with it."

TZubiri 5 hours ago|
This seems irrelevant as the issue talks about being exploitable with a crafted HTML page, no mention of JS. If true, you would be able to be hit without js enabled.
krackers 5 hours ago||
It mentions a type confusion in V8. Is it possible to trigger that without JS enabled?

The "all chromium versions" part of the title is also misleading, most browser CVEs do not distinguish between "untested lower bound" vs "affects all" (even though it seems like it'd be trivial to bisect).

b8 3 hours ago||
$1k for this vuln is laughable. If the researcher wrote an exploit as the nday exploit devs did and sold it in the gray market they would of got significantly more.
eschaton 2 hours ago|
Anyone who sells such an exploit should go to prison.
b--l 1 hour ago||
Agreed--if you can catch them of course.
radium3d 5 hours ago||
Doesn't everyone else immediately update everything on their computer before they start doing anything?
Invictus0 5 hours ago|
what planet are you living on
petra303 8 hours ago|
Only a score of 8.8?
teravor 8 hours ago|
RCE inside sandbox, so requires chaining with another 0day.
zahlman 7 hours ago|||
What exactly does "RCE inside sandbox" describe that goes beyond "the webpage can supply arbitrary JavaScript and the JavaScript engine executes it", but is still isolated from the system?
StilesCrisis 6 hours ago|||
Chrome runs webpages in individual sandbox processes with very low privileges, as a defense-in-depth strategy. It generally requires at least two exploits to actually affect a user--first, get RCE in a sandboxed process, then find a separate vulnerability that lets you escape the sandbox process entirely. For this bug to have actually been used in the wild, there was almost certainly a second bug as well.
jimrandomh 7 hours ago||||
It means it can execute native code inside the sandbox, as opposed to Javascript. While still sandboxed, this lets it access some parts of the attack surface that JS would not have been able to, some of which may have other exploits that allow escaping the rest of the way.
jnwatson 7 hours ago||||
It means it can execute arbitrary machine code in the sandbox.
r_lee 7 hours ago|||
I think people would like to understand what the "sandbox" is here and what isolation does it provide, is it an unprivileged process? something chromium specific? a v8/JS thing? etc.
ranger_danger 7 hours ago||
Seems to use OS-specific kernel syscall filtering facilities.

Windows: https://chromium.googlesource.com/chromium/src/+/HEAD/docs/d...

Linux: https://chromium.googlesource.com/chromium/src/+/0e94f26e8/d...

Genwald 7 hours ago|||
V8 also has its own sandbox, which I believe exists in that sandbox. I assume that's the one this exploit has RCE in, but its unclear.

https://chromium.googlesource.com/v8/v8.git/+/refs/heads/mai...

insanitybit 6 hours ago||
I would assume in this case that there's full renderer control, not just a bypass of the in-process isolation.
r_lee 7 hours ago|||
great link, thanks
zahlman 7 hours ago||||
Okay, and why is that more of a security risk than executing arbitrary JavaScript in the sandbox?
arcfour 6 hours ago|||
Among other things, JavaScript in the browser has no way to even express "kill PID 1234 on the user's machine" or "list the contents of `C:\Users\Documents` and upload all of the files" or "spawn cmd.exe on the user's machine". How would you even do these things if you could run any JavaScript in the browser? You can't.

However, chrome.exe itself does because it's a native application, as is the sandboxed JavaScript interpreter inside of chrome.exe.

(This is a very oversimplified explanation but I think this is the disconnect people are having)

bawolff 5 hours ago||
> JavaScript in the browser has no way to even express ... "list the contents of `C:\Users\Documents` and upload all of the files"

this is besides the point, but javascript has the file system api.

anyways to your broad point, i dont think this is convincing. What's the difference between not having an api vs having an api that is disabled (e.g. the syscall exists but is filtered). Either way you are not taking the action. RCE in the sandbox is an important step in the bigger exploit chain, but not because you can express things in the traditional syscalls inside the sandbox.

insanitybit 6 hours ago||||
Because Javascript theoretically can't just access files on disk. Control over the render would let you do that, if not for the process level sandbox, which constraints things like file access, system, calls, etc.

But the process is still more capable than the VM. The process can talk to other processes via IPC, for example.

That's why you don't go from "javascript -> computer is taken over", instead you go from "javascript -> renderer control -> computer is taken over".

r_lee 7 hours ago||||
because with proper code exec you can trigger other bugs to escalate beyond the sandbox, whereas with JS you'd have to find a bug to escape from JS to native

can't get a proper ios/Android RCE with just JS code exec

p-e-w 7 hours ago|||
It can do some things that JS can’t do, such as invalid pointer writes. But you are correct that this doesn’t automatically imply system access.
TacticalCoder 6 hours ago|||
> It means it can execute arbitrary machine code in the sandbox.

Well which is precisely why we have sandboxes.

To me "executing arbitrary code in the sandbox" is similar to "I don't give a flying fuck for it's what a sandbox is for".

More information is needed. As someone commented: this has to be paired with at least another exploit to make anything remotely useful.

A sandbox is a sandbox. We want to understand how "code running in a sandbox" is "actively exploited".

johnsmith1840 7 hours ago||||
Memory isolation having one tab or account open on your bank and another on this page does not mean it could leak across the sandbox and steal bank account details but anything inside of your general page content can be lost
TZubiri 5 hours ago||||
This doesn't affect the score though, the reason there's 1.2 points less than the max is because there is a Required User Interaction. The user needs to visit a specific html page.

Even with the sandbox protection layer, the rest of the parameters are maxed out.

iririririr 7 hours ago|||
what is online ad networks for $100, alex
jeremyjh 5 hours ago|||
I don't know why this is being downvoted. This is called malvertising and its one of the most significant vectors for exploiting a vulnerability like this. Its happened multiple times over the last two decades.

My read of Google's disclosure is that there is likely no known escape from the sandbox. I don't agree this would be reported this way just because "user action" like "using web browser" is required. Even if this individual CVE is correctly an 8.8 there would be a critical assessment of a known chain. The only reason there wouldn't be, would be if the other vulnerability is known to Google but has no patch yet.

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