Arch Linux: 201410-1 Medium Severity: Rsyslog Remote Denial Of Service

Arch Linux Security Advisory ASA-201410-1
========================================
Severity: Medium
Date    : 2014-10-01
CVE-ID  : CVE-2014-3634
Package : rsyslog
Type    : Denial of service
Remote  : Yes
Link    : https://wiki.archlinux.org/title/CVE-2014

Summary
======
The package rsyslog before version 8.4.1-1 is
vulnerable to a remote denial of service.

Resolution
=========
Upgrade to 8.4.1-1.

# pacman -Syu "rsyslog>=8.4.1-1"

The problem has been fixed upstream in version 8.4.1.

Workaround
=========
It is possible to prevent unauthorized remote hosts from sending syslog
messages to vulnerable hosts, for example by using a firewall.

Description
==========
Sending a syslog message containing an invalid PRI value to a
vulnerable rsyslog server accepting remote message will trigger a denial
of service by crashing the rsyslog process.

Impact
=====
A remote attacker authorized to send syslog messages can cause the
syslog server to segfault, causing a denial of service.
According to the rsyslog project leader, under certain preconditions it
may possibly lead to remote code execution [1]. The default
configuration is safe from these preconditions.

References
=========
[1] https://www.rsyslog.com/remote-syslog-pri-vulnerability/
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2014-3634
https://bugs.archlinux.org/task/42200