User with restricted rights is able to shutdown machine while ssh superuser is connected
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
openssh (Ubuntu) |
Triaged
|
Low
|
Unassigned |
Bug Description
I was updating an xubuntu 32bit karmic machine with a ubuntu 64bit karmic machine via ssh and elevated privileges (sudo bash).
A user with a restricted account was able to shut down the xubuntu machine while this ssh session was running. This was not the case in jaunty, the xubuntu machine reported dpkg interruption after I restarted it.
This problem is reproducible most of the time, but it happened once that the xubuntu machine asked for a password before shutting down. Even if the right password was given it wouldn't shut down (which isn't much of a problem because it should never shut down when a superuser is logged in (in my opinion)). But once the superuser had logged out the machine still wouldn't shut down (which is a problem again)...
I am not sure which package is to blame here, so I opted for ssh (but it could also be something to do with user-privileges or shutdown-procedures etc.).
I also wasn't sure if this was a security issue. It's not an exploit or something but it could get quite ugly if stuff like this can happen.
ProblemType: Bug
Architecture: amd64
Date: Sat Oct 3 21:23:23 2009
DistroRelease: Ubuntu 9.10
NonfreeKernelMo
Package: ssh (not installed)
ProcEnviron:
LANG=en_US.UTF-8
SHELL=/bin/bash
ProcVersionSign
SourcePackage: openssh
Uname: Linux 2.6.31-11-generic x86_64
security vulnerability: | yes → no |
visibility: | private → public |
Changed in openssh (Ubuntu): | |
status: | Incomplete → New |
Changed in openssh (Ubuntu): | |
status: | New → Incomplete |
As an extra note I didn't ssh with superuser but I ran "sudo bash" inside the ssh session and started upgrading when this happened the first time. Later on I tried with starting a program (like "sudo vi") and just plain "sudo bash" and it happened 3 times again (normal user could shut down the machine), and once I got a password request on the xubuntu machine (and it wouldn't shut down at all even if ssh was disconnected).