RHSA-2011:0881 - Security Advisory

Topic

An updated jabberd package that fixes one security issue is now available
for Red Hat Network Proxy 5.4.1 for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having low
security impact. A Common Vulnerability Scoring System (CVSS) base score,
which gives a detailed severity rating, is available from the CVE link in
the References section.

Description

This package provides jabberd 2, an Extensible Messaging and Presence
Protocol (XMPP) server used for XML based communication.

It was found that the jabberd daemon did not properly detect recursion
during entity expansion. A remote attacker could provide a
specially-crafted XML file containing a large number of nested entity
references, which once processed by the jabberd daemon, could lead to a
denial of service (excessive memory and CPU consumption). (CVE-2011-1755)

Red Hat would like to thank Nico Golde of the Debian Security Team for
reporting this issue. The Debian Security Team acknowledges Wouter
Coekaerts as the original reporter.

Users of Red Hat Network Proxy 5.4.1 are advised to upgrade to this updated
jabberd package, which resolves this issue. For this update to take effect,
Red Hat Network Proxy must be restarted. Refer to the Solution section for
details.

Solution

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/kb/docs/DOC-11259

Run the following command to restart the Red Hat Network Proxy server:

# rhn-proxy restart

Affected Products

• Red Hat Satellite Proxy 5.4 for RHEL 5 x86_64
• Red Hat Satellite Proxy 5.4 for RHEL 5 s390x
• Red Hat Satellite Proxy 5.4 for RHEL 5 i386

Fixes

• BZ - 700390 - CVE-2011-1755 jabberd: DoS via the XML "billion laughs attack"

CVEs

• CVE-2011-1755

References

• https://access.redhat.com/security/updates/classification/#low