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.
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.