Gentoo Forums
Gentoo Forums
Gentoo Forums
Quick Search: in
[ GLSA 200509-15 ] util-linux: umount command validation error
View unanswered posts
View posts from last 24 hours

 
Reply to topic    Gentoo Forums Forum Index News & Announcements
View previous topic :: View next topic  
Author Message
GLSA
Veteran
Veteran


Joined: 12 May 2004
Posts: 1471

PostPosted: Tue Sep 20, 2005 2:31 pm    Post subject: [ GLSA 200509-15 ] util-linux: umount command validation err Reply with quote

Gentoo Linux Security Advisory

Title: util-linux: umount command validation error (GLSA 200509-15)
Severity: high
Exploitable: local
Date: September 20, 2005
Bug(s): #105805
ID: 200509-15

Synopsis

A command validation error in umount can lead to an escalation of privileges.

Background

util-linux is a suite of useful Linux programs including umount, a program used to unmount filesystems.

Affected Packages

Package: sys-apps/util-linux
Vulnerable: < 2.12q-r3
Unaffected: >= 2.12q-r3
Architectures: All supported architectures


Description

When a regular user mounts a filesystem, they are subject to restrictions in the /etc/fstab configuration file. David Watson discovered that when unmounting a filesystem with the '-r' option, the read-only bit is set, while other bits, such as nosuid or nodev, are not set, even if they were previously.

Impact

An unprivileged user facing nosuid or nodev restrictions can umount -r a filesystem clearing those bits, allowing applications to be executed suid, or have device nodes interpreted. In the case where the user can freely modify the contents of the filesystem, privilege escalation may occur as a custom program may execute with suid permissions.

Workaround

Two workarounds exist, first, the suid bit can be removed from the umount utility, or users can be restricted from mounting and unmounting filesystems in /etc/fstab.

Resolution

All util-linux users should upgrade to the latest version:
Code:
# emerge --sync
# emerge --ask --oneshot --verbose ">=sys-apps/util-linux-2.12q-r3"


References

CAN-2005-2876


Last edited by GLSA on Sun May 07, 2006 4:58 pm; edited 1 time in total
Back to top
View user's profile Send private message
Display posts from previous:   
Reply to topic    Gentoo Forums Forum Index News & Announcements All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum