cdrtools: Local root vulnerability in cdrecord if set SUID root

1. Gentoo Linux Security Advisory

Advisory Reference	GLSA 200409-18 / cdrtools
Release Date	September 14, 2004
Latest Revision	September 14, 2004: 01
Impact	high
Exploitable	local

Package	Vulnerable versions	Unaffected versions	Architecture(s)
app-cdr/cdrtools	<= 2.01_alpha37	>= 2.01_alpha37-r1, revision >= 2.01_alpha28-r2	All supported architectures

Related bugreports: #63187

Synopsis

cdrecord, if manually set SUID root, is vulnerable to a local root exploit allowing users to escalate privileges.

2. Impact Information

Background

The cdrtools package is a set of tools for CD recording, including the popular cdrecord command-line utility.

Description

Max Vozeler discovered that the cdrecord utility, when set to SUID root, fails to drop root privileges before executing a user-supplied RSH program. By default, Gentoo does not ship the cdrecord utility as SUID root and therefore is not vulnerable. However, many users (and CD-burning front-ends) set this manually after installation.

Impact

A local attacker could specify a malicious program using the $RSH environment variable and have it executed by the SUID cdrecord, resulting in root privileges escalation.

3. Resolution Information

Workaround

As a workaround, you could remove the SUID rights from your cdrecord utility :

Code Listing 3.1: Workaround

# chmod a-s /usr/bin/cdrecord

Resolution

All cdrtools users should upgrade to the latest version:

Code Listing 3.2: Resolution

# emerge sync
# emerge -pv ">=app-cdr/cdrtools-2.01_alpha37-r1"
# emerge ">=app-cdr/cdrtools-2.01_alpha37-r1"

4. References

CAN-2004-0806

Page updated September 14, 2004

Summary: This is a Gentoo Linux Security Advisory

Security Team
Contact Address

Donate to support our development efforts.