A log4net security update has been released for Debian GNU/Linux 8 LTS to address an XML external entity vulnerability.

DLA 2211-1: log4net security update

Package : log4net
Version : 1.2.10+dfsg-6+deb8u1

It was discovered that there was an XML external entity vulnerability
in log4net, a logging API for the ECMA Common Language Infrastructure
(CLI), sometimes referred to as "Mono".

This type of attack occurs when XML input containing a reference to
an internet-faced entity is processed by a weakly configured XML
parser. This attack may lead to the disclosure of confidential data,
denial of service, server side request forgery as well as other
system impacts.

For Debian 8 "Jessie", this issue has been fixed in log4net version
1.2.10+dfsg-6+deb8u1.

We recommend that you upgrade your log4net packages.

Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at:   https://wiki.debian.org/LTS