316
Over 5,300 GitLab servers exposed to zero-click account takeover attacks
(www.bleepingcomputer.com)
this post was submitted on 28 Jan 2024
316 points (99.1% liked)
Technology
59311 readers
5302 users here now
This is a most excellent place for technology news and articles.
Our Rules
- Follow the lemmy.world rules.
- Only tech related content.
- Be excellent to each another!
- Mod approved content bots can post up to 10 articles per day.
- Threads asking for personal tech support may be deleted.
- Politics threads may be removed.
- No memes allowed as posts, OK to post as comments.
- Only approved bots from the list below, to ask if your bot can be added please contact us.
- Check for duplicates before posting, duplicates may be removed
Approved Bots
founded 1 year ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
Jesus Christ. Their frontend was sending a list of recipients to the backend. That's an intern developer level of fuck up, in their login system, no less.
If this got past them, it's a sign of deep problems.
Can you explain in a bit more detail what you understand was happening?
Gitlab has a backend, which runs on a server, and a frontend, which runs in all the user's browsers. When the user does anything it sends some network requests to the backend in order to save the changes the user has made, send the necessary emails or create a session, etc.
The thing with this architecture is the backend and frontend are effectively separate apps. Also as the frontend is running remotely on the attacker's computer the attacker can change it to behave however they want. The backend can't trust the frontend to "do the right thing", ever. The backend needs to assume the frontend will do every bad and silly thing possible, and treat anything coming from the frontend with maximum suspicion.
So you simply can't allow the frontend code to provide a list of email addresses to send an email to, because it'll allow the attacker to send emails to anywhere. Where the email goes to needs to be determined by the backend. The frontend should only be concerned with hiding and showing stuff in the UI, and pretty much all intelligence and business logic needs to reside on the server where we control the code and environment. A good understanding of the roles and responsibilities of the front vs back is a fundamental concept and if the developer hasn't grasped this then they're going to introduce security problems everywhere they go.
This is one of many pitfalls of the "frontend + backend" architecture. I vastly prefer to build monoliths instead.
Not the commenter but it seems like the parameters of the HTTP Get/Post weren't protected/checked. The API was likely something like: Email to reset: string(email account to reset) But it accepted something like: [string(email account to reset), string (email to which the reset mail is sent to)]
Little Bobby Tables? Or would that be an XHR attack?
Bobby table, this, buffer overflow... Are all similar in spirit.
Bobby table is a way for hiding the malicious SQL query after a normal query (in that case after the select with "Bobby" you inject the malicious drop table)
In this case after the normal email (that normally would serve for both identifying the user and for the mail to send the recovering mail), the attacker sends two mails, the first is fo identifying the user the second to send the recovering mail
In the case of buffer overflow you inject malicious code after normal(-ish) data
It's not an XHR attack since for the mail recovery workflow you don't need an authenticated session.
To be a bit more compassionate to the developers, this is probably some dynamic typing problem. Probably ruby is "smart" into understand that an array can contain strings after all... So an array of strings is as good as a string... But here we go into static vs dynamic typing.... And it's a bit of religious war (fun fact in 2011 i was advocating with Guido Van Rossum in having at least an optional static typing check in Python - at the time the discussion was how to make python faster/compiled - and he was borderline mocking me 😅 and few years after pytypes but still no compilation at horizon 😂)