Fcron: Multiple vulnerabilities

1. Gentoo Linux Security Advisory

Advisory Reference	GLSA 200411-27 / fcron
Release Date	November 18, 2004
Latest Revision	November 18, 2004: 01
Impact	normal
Exploitable	local

Package	Vulnerable versions	Unaffected versions	Architecture(s)
sys-process/fcron	<= 2.9.5	revision >= 2.0.2, >= 2.9.5.1	All supported architectures

Related bugreports: #71311

Synopsis

Multiple vulnerabilities in Fcron can allow a local user to potentially cause a Denial of Service.

2. Impact Information

Background

Fcron is a command scheduler with extended capabilities over cron and anacron.

Description

Due to design errors in the fcronsighup program, Fcron may allow a local user to bypass access restrictions (CAN-2004-1031), view the contents of root owned files (CAN-2004-1030), remove arbitrary files or create empty files (CAN-2004-1032), and send a SIGHUP to any process. A vulnerability also exists in fcrontab which may allow local users to view the contents of fcron.allow and fcron.deny (CAN-2004-1033).

Impact

A local attacker could exploit these vulnerabilities to perform a Denial of Service on the system running Fcron.

3. Resolution Information

Workaround

Make sure the fcronsighup and fcrontab binaries are only executable by trusted users.

Resolution

All Fcron users should upgrade to the latest version:

Code Listing 3.1: Resolution

# emerge --sync
# emerge --ask --oneshot --verbose ">=sys-process/fcron-2.0.2"

4. References

Updated November 18, 2004

Summary: This is a Gentoo Linux Security Advisory

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