util-linux umount privilege escalation (SSA:2005-255-02)

Posted by Philipp Esselbach on: 09/13/2005 04:39 AM [ Print | 0 comment(s) ]

New util-linux packages are available for Slackware 8.1, 9.0, 9.1, 10.0, 10.1, and -current to fix a security issue with umount. A bug in the '-r' option could allow flags in /etc/fstab to be improperly dropped on user-mountable volumes, allowing a user to gain root privileges.

For more details, see David Watson's post to BugTraq:

http://www.securityfocus.com/archive/1/410333

Here are the details from the Slackware 10.1 ChangeLog:
+--------------------------+
patches/packages/util-linux-2.12p-i486-2.tgz: Patched an issue with
umount where if the umount failed when the '-r' option was used, the
filesystem would be remounted read-only but without any extra flags
specified in /etc/fstab. This could allow an ordinary user able to
mount a floppy or CD (but with nosuid, noexec, nodev, etc in
/etc/fstab) to run a setuid binary from removable media and gain
root privileges.
Reported to BugTraq by David Watson:
http://www.securityfocus.com/archive/1/410333
(* Security fix *)
+--------------------------+

Where to find the new packages:
+-----------------------------+

Updated package for Slackware 8.1:
ftp://ftp.slackware.com/pub/slackware/slackware-8.1/patches/packages/util-linux-2.11r-i386-3.tgz

Updated package for Slackware 9.0:
ftp://ftp.slackware.com/pub/slackware/slackware-9.0/patches/packages/util-linux-2.11z-i386-2.tgz

Updated package for Slackware 9.1:
ftp://ftp.slackware.com/pub/slackware/slackware-9.1/patches/packages/util-linux-2.12-i486-2.tgz

Updated package for Slackware 10.0:
ftp://ftp.slackware.com/pub/slackware/slackware-10.0/patches/packages/util-linux-2.12a-i486-2.tgz

Updated package for Slackware 10.1:
ftp://ftp.slackware.com/pub/slackware/slackware-10.1/patches/packages/util-linux-2.12p-i486-2.tgz

Updated package for Slackware -current:
ftp://ftp.slackware.com/pub/slackware/slackware-current/slackware/a/util-linux-2.12p-i486-2.tgz

MD5 signatures:
+-------------+

Slackware 8.1 package:
3b3025faf0a40428f2861fa2967c13d3 util-linux-2.11r-i386-3.tgz

Slackware 9.0 package:
41b08961548899ca10fa93d16a7ab516 util-linux-2.11z-i386-2.tgz

Slackware 9.1 package:
4890b834bac6d7490c1daf5bc7bbff55 util-linux-2.12-i486-2.tgz

Slackware 10.0 package:
3e628cf4d6db843a1dd63e2fa7f3aba1 util-linux-2.12a-i486-2.tgz

Slackware 10.1 package:
01722ab0146969c6cde9f99698864606 util-linux-2.12p-i486-2.tgz

Slackware -current package:
21e318a9f04dc6588916945713312bf3 util-linux-2.12p-i486-2.tgz

Installation instructions:
+------------------------+

Upgrade the package as root:
# upgradepkg util-linux-2.12p-i486-2.tgz

+-----+

Slackware Linux Security Team
http://slackware.com/gpg-key
security@slackware.com