Vixie Cron: Privilege Escalation

Security Team  Contact Address

Updated June 09, 2006

1.  Gentoo Linux Security Advisory

Version Information

Advisory Reference GLSA 200606-07 / vixie-cron
Release Date June 09, 2006
Latest Revision June 09, 2006: 01
Impact high
Exploitable local
Package Vulnerable versions Unaffected versions Architecture(s)
sys-process/vixie-cron < 4.1-r9 >= 4.1-r9 All supported architectures

Related bugreports: #134194

Synopsis

Vixie Cron allows local users to execute programs as root.

2.  Impact Information

Background

Vixie Cron is a command scheduler with extended syntax over cron.

Description

Roman Veretelnikov discovered that Vixie Cron fails to properly check whether it can drop privileges accordingly if setuid() in do_command.c fails due to a user exceeding assigned resource limits.

Impact

Local users can execute code with root privileges by deliberately exceeding their assigned resource limits and then starting a command through Vixie Cron. This requires resource limits to be in place on the machine.

3.  Resolution Information

Workaround

There is no known workaround at this time.

Resolution

All Vixie Cron users should upgrade to the latest version:

Code Listing 3.1: Resolution

# emerge --sync
# emerge --ask --oneshot --verbose ">=sys-process/vixie-cron-4.1-r9"

4.  References