BugTraq
aterm 0.4.2 tty permission weakness Jul 13 2004 04:04PM
Maarten Tielemans (TTIelu_DaInfraCrew hotmail com) (4 replies)
Re: [security] aterm 0.4.2 tty permission weakness Jul 14 2004 10:26AM
lorenzo (lagrespan gmail com)
On 13 Jul 2004 16:04:18 -0000, Maarten Tielemans
<ttielu_dainfracrew (at) hotmail (dot) com [email concealed]> wrote:
> Aterm has an issue with creating a terminal.
> A quick 'ls ?al' on a aterm with 'mesg y' shows:
> crw--w--w- 1 alsdk users 5, 3 Jul 13 17:27 /dev/ttyp3
> with 'mesg n':
> crw-----w- 1 alsdk users 5, 3 Jul 13 17:28 /dev/ttyp3

on debian unstable, with aterm 0.4.2:

[1] k@nemo:~ 4$ aterm -V
aterm version 0.4.2

let's see who's online

[2] k@nemo:~ 4$ w
12:19:27 up 25 min, 2 users, load average: 0.02, 0.05, 0.10
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
k pts/1 :0.0 11:57 23.00s 0.15s 0.03s /usr/bin/aterm
k pts/4 :0.0 12:19 0.00s 0.15s 0.00s w

now let's see their pts:

[3] k@nemo:~ 4$ ls -la /dev/pts/?
crw------- 1 k tty 136, 1 Jul 14 12:19 /dev/pts/1
crw--w---- 1 k tty 136, 4 Jul 14 12:19 /dev/pts/4

disabling messages

[4] k@nemo:~ 4$ mesg n
[5] k@nemo:~ 4$ ls -la /dev/pts/4
crw------- 1 k tty 136, 4 Jul 14 12:19 /dev/pts/4

looks ok to me.

> 1) World (nobody) is able to 'echo' or 'cat' towards the terminal
> echo "hello" >> /dev/ttyp3
> cat mkdir >> /dev/ttyp3

[6] k@nemo:~ 4$ cat mkdir >> /dev/pts/4
cat: mkdir: No such file or directory
..what was the purpose of that? insecure file creation?
the worst thing you could do is

echo "y0u have b33n 0wn3d" >> /dev/pts/x

> Advice: use xterm

well this won't solve the problem. what if xterm has some other small
vulnerability? would you advice to use kconsole next time?

--
:lorenzo a. grespan --- GNU/Linux User Group Mantova - Italy
http://lorien.lacasadeifili.net
GPG Key fingerprint = 5372 1B49 9E61 747C FB9A 4DAE 5D2A A9A0 74B4 8F1A

[ reply ]
Re: aterm 0.4.2 tty permission weakness Jul 14 2004 09:59AM
Sebastian Hans (hanss in tum de)
Re: aterm 0.4.2 tty permission weakness Jul 14 2004 07:47AM
Armin Wolfermann (aw osn de)
Re: aterm 0.4.2 tty permission weakness Jul 14 2004 04:10AM
Coleman Kane (cokane cokane org)


 

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