XnView: Privilege escalation

1. Gentoo Linux Security Advisory

Advisory Reference	GLSA 200512-18 / xnview
Release Date	December 30, 2005
Latest Revision	May 22, 2006: 02
Impact	normal
Exploitable	local

Package	Vulnerable versions	Unaffected versions	Architecture(s)
x11-misc/xnview	< 1.70-r1	>= 1.70-r1	Intel compatible

Related bugreports: #117063

Synopsis

XnView may search for shared libraries in an untrusted location, potentially allowing local users to execute arbitrary code with the privileges of another user.

2. Impact Information

Background

XnView is an efficient multimedia viewer, browser and converter, distributed free for non-commercial use.

Description

Krzysiek Pawlik of Gentoo Linux discovered that the XnView package for IA32 used the DT_RPATH field insecurely, causing the dynamic loader to search for shared libraries in potentially untrusted directories.

Impact

A local attacker could create a malicious shared object that would be loaded and executed when a user attempted to use an XnView utility. This would allow a malicious user to effectively hijack XnView and execute arbitrary code with the privileges of the user running the program.

3. Resolution Information

Workaround

The system administrator may use the chrpath utility to remove the DT_RPATH field from the XnView utilities:

Code Listing 3.1: Workaround

# emerge app-admin/chrpath
# chrpath --delete /opt/bin/nconvert /opt/bin/nview /opt/bin/xnview

Resolution

All XnView users on the x86 platform should upgrade to the latest version:

Code Listing 3.2: Resolution

# emerge --sync
# emerge --ask --oneshot --verbose ">=x11-misc/xnview-1.70-r1"

4. References

CVE-2005-4595

Updated December 30, 2005

Summary: This is a Gentoo Linux Security Advisory

Security Team
Contact Address

Donate to support our development efforts.