GitLab Remote Code Execution - Integer Overflow issue
docs.gitlab.com124 points by artooro 3 hours ago
124 points by artooro 3 hours ago
Awesome find by https://hackerone.com/joaxcar and it's a little bit frightening that this severe of a bug isn't the biggest security vulnerability of today
What a great week security wise!
At least second regex related CVE in GitLab in the past few weeks. Awful to see that the endpoint is reachable unauthenticated, but I'm glad that they provide guidance in how to check the logs for attempts of exploitation
As far as I can tell, it requires forcing GitLab to render a malicious org-mode file. I don't really see a way to do that without authenticating and uploading one. Am I missing something?
Is this a bug in GitLab or in Ruby? It's hard to tell from the report and the patch...
Back in perl 5.8 and older, the regex engine worked by recusing at the level of C functions, and so you could trigger stack overflows by giving it large strings.
Is this similar?
I wonder why gitlab even has its own regex compiler. Or is this a vulnerability in an underlying library or programming language?
If you're patching a fleet, gitlab-rake gitlab:env:info gives you the exact version per node, faster than guessing from the omnibus package name.
possible bug? or too soon to check? :)
after updating a pop-up still shows:
"You are currently on version 19.5.1! We strongly recommend upgrading your GitLab installation immediately."
while 19.5.1 should be the latest and fixed version
Their update checker has never worked very well. It takes hours to stop getting the upgrade warning inside of the GitLab dashboard.
I am concerned for my self hosted servers, well only hope is tailscale should be entirely secure, and egress is filtered heavily... If that doesn't work my home lab is fucked.
Any suggestions folks, not even my terminally online self can handle all of these.
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"CVSS 10.0" isn't in the headline here and a CVSS of 10 doesn't actually mean anything.
Deeper in the article: https://docs.gitlab.com/releases/patches/patch-release-gitla...
GitLab has remediated an issue that, under certain conditions, could have allowed an unauthenticated user to execute arbitrary code on the GitLab server due to integer overflow when compiling a specially crafted regular expression. (...)
CVSS 10.0 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H)
Here, CVSS 10.0 means arbitrary remote code execution.
"Arbitrary RCE" does mean something. "CVSS 10.0" does not. We should be using the article headline here.
Truth be told, I don't think that "GitLab Critical Patch Release: 19.5.1, 19.4.3, 19.3.6, 19.2.9, 19.1.9, 19.0.10, 18.11.13" is a more descriptive title, even taking the HN guidelines into account. It could be better, sure, but it's not horrible (IMO).
It's an editorialization. The submitter is saying something about the importance of CVSS that the article does not. A better title would say "Remote Code Execution" where it says "CVSS 10.0" now.
Because "10 out of 10" is a better headline for the average reader than "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H".
Sometimes CVSS 10 "oversells" the true severity of a bug but this doesn't seem to be one of those cases.
>CVSS of 10 doesn't actually mean anything.
Might you perchance be exaggerating?
No? CVSS is a Ouija board. Citrix directory traversal got scored 10.0. So did a Cisco Broadworks SSO bypass. Meanwhile, Shellshock did not.
CVSS is like the Pitchfork Music ratings scale. It communicates false precision, and it's easy to point to places where that precision misleads (D-plan's "Emergency & I" is not better than every Yo La Tengo album).
Have you read signal/noise theory? That a signal isn't perfect (that it contains false positives or positive falses in case of binary signals, or that it has a delta between the signal and the underlying phenomenon) doesn't mean that it carries no information.
For example if I cry wolf 50% of the time, but 100% of the times there's a wolf I cry wolf. Then no matter what the frequency of wolf sightings are, my crying wolf carries some information (unless there's always a wolf). Assume there's a wolf 1% of the nights, then I will cry wolf 50% of the time, and you only need to check for a wolf 50% of the nights rather than 100%.
It's worth noting that there's still technically signal even if I sometimes miss a wolf, even if you may choose to ignore that signal in order to pursue 100% accuracy yourself.
It's more like: you work as an animal spotter, and if you tell people you saw a hamster, you'll get no glory. So obviously you spotted a direwolf at least 12 feet tall.