Bugtraq mailing list archives
Re: Sudo tricks
From: Javor Ninov <drfrancky () securax org>
Date: Wed, 29 Mar 2006 13:02:56 +0300
If we have access to another user ~/ why installing root kit and not use some trivial attack ? like path attack as example or clean exec ? installing a root kit on monitored system will yell alarms. as i previously said if we have access to another user ~/ we have full access to all privileges that this user have. the main issue here is how we get access to the user ~/ about the local virus .. in the example given by the author we compromise the user A which have sudo to root if we have knowledge of the target system we can easily make automated program that compromises other users accounts but .. /there is always but/ in order to compromise other users we will need bigger privs than the user that we attack or some system wide exploit /which is sort of bigger privs/. then if we have those privs why bothering writing a automated program and not compromise them at once ? the only scenario that this is useful is if we have a user A which can execute commands in the context of a user B which can execute commands in context of root in that case if we have a way to compromise user A's ~/ then we can make some automated program that gathers information ,even have some predefined logic about handling some commands enabled in /etc/sudoers, and then exploit it. but thats a very rare case. p.s. sudo to root without pass ... c'mon you have to be kidding me, right ? Javor Ninov aka DrFrancky drfrancky[shift + 2]securax.org securitydot.net Steven M. Christey wrote:
So, in other words, all you need in order to get root access is a rootkit, your shell script, and root access? Ummm... I don't get it.I was also confused by this. However, one guess is that by compromising an unprivileged account and creating command aliases to run trojaned su and sudo programs, the attacker can hopefully gain access to another account, then another, etc. By using these sudo "privilege chains" the attacker might eventually obtain root access. This attack would be slightly virus-like in behavior, although local to the system. And it might accomplish less, and more slowly, than if the attacker used some other means to determine the explicit su/sudo relationships and exploit them directly (e.g. sudo -l to list allowed commands?) And this attack sounds like it's entirely dependent on whether or not such a chain even exists on the system. Insert standard text about the likelihood of easier attack vectors here. Just a guess, though. Interesting notion of a local-only "virus" to compromise users on a multi-user system, although it seems like just another way to exploit trust relationships once you've gained access to a local account. - Steve
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Current thread:
- Sudo tricks John Richard Moser (Mar 23)
- Re: Sudo tricks Dave Korn (Mar 25)
- Re: Sudo tricks Kyle Wheeler (Mar 27)
- Re: Sudo tricks Thomas M. Payerle (Mar 28)
- Re: Sudo tricks Krzysztof Halasa (Mar 29)
- RE: Sudo tricks Burton Strauss (Mar 31)
- <Possible follow-ups>
- Re: Sudo tricks Steven M. Christey (Mar 28)
- Re: Sudo tricks Javor Ninov (Mar 31)
- Re: Sudo tricks Dave Korn (Mar 25)