GLSA 200704-11: Vixie Cron: Denial of Service

http://security.gentoo.org/

Severity:	low
Title:	Vixie Cron: Denial of Service
Date:	04/16/2007
Bugs:	#164466
ID:	200704-11

Synopsis

The Gentoo implementation of Vixie Cron is vulnerable to a local Denial of Service.

Background

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

Affected packages

Package	Vulnerable	Unaffected	Architecture(s)
sys-process/vixie-cron	< 4.1-r10	>= 4.1-r10	All supported architectures

Description

During an internal audit, Raphael Marichez of the Gentoo Linux Security Team found that Vixie Cron has weak permissions set on Gentoo, allowing for a local user to create hard links to system and users cron files, while a st_nlink check in database.c will generate a superfluous error.

Impact

Depending on the partitioning scheme and the "cron" group membership, a malicious local user can create hard links to system or users cron files that will trigger the st_link safety check and prevent the targeted cron file from being run from the next restart or database reload.

Workaround

There is no known workaround at this time.

Resolution

All Vixie Cron users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=sys-process/vixie-cron-4.1-r10"

References

CVE-2007-1856

Availability

This GLSA and any updates to it are available for viewing at the Gentoo Security Website: http://security.gentoo.org/glsa/glsa-200704-11.xml

Concerns?

Security is a primary focus of Gentoo Linux and ensuring the confidentiality and security of our users machines is of utmost importance to us. Any security concerns should be addressed to security@gentoo.org or alternatively, you may file a bug at https://bugs.gentoo.org.