Moderate: apr-util security update

Updated apr-util packages that fix multiple security issues are now
available for Red Hat Enterprise Linux 4 and 5.

This update has been rated as having moderate security impact by the Red
Hat Security Response Team.

apr-util is a utility library used with the Apache Portable Runtime (APR).
It aims to provide a free library of C data structures and routines. This
library contains additional utility interfaces for APR; including support
for XML, LDAP, database interfaces, URI parsing, and more.

An off-by-one overflow flaw was found in the way apr-util processed a
variable list of arguments. An attacker could provide a specially-crafted
string as input for the formatted output conversion routine, which could,
on big-endian platforms, potentially lead to the disclosure of sensitive
information or a denial of service (application crash). (CVE-2009-1956)

Note: The CVE-2009-1956 flaw only affects big-endian platforms, such as the
IBM S/390 and PowerPC. It does not affect users using the apr-util package
on little-endian platforms, due to their different organization of byte
ordering used to represent particular data.

A denial of service flaw was found in the apr-util Extensible Markup
Language (XML) parser. A remote attacker could create a specially-crafted
XML document that would cause excessive memory consumption when processed
by the XML decoding engine. (CVE-2009-1955)

A heap-based underwrite flaw was found in the way apr-util created compiled
forms of particular search patterns. An attacker could formulate a
specially-crafted search keyword, that would overwrite arbitrary heap
memory locations when processed by the pattern preparation engine.
(CVE-2009-0023)

All apr-util users should upgrade to these updated packages, which contain
backported patches to correct these issues. Applications using the Apache
Portable Runtime library, such as httpd, must be restarted for this update
to take effect.

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

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

503928 - CVE-2009-0023 apr-util heap buffer underwrite
504390 - CVE-2009-1956 apr-util single NULL byte buffer overflow
504555 - CVE-2009-1955 apr-util billion laughs attack

https://www.redhat.com/security/data/cve/CVE-2009-0023.html
https://www.redhat.com/security/data/cve/CVE-2009-1955.html
https://www.redhat.com/security/data/cve/CVE-2009-1956.html
http://www.redhat.com/security/updates/classification/#moderate