Exim is a mail transport agent (MTA) developed at the University of Cambridge for use on Unix systems connected to the Internet.
An integer overflow flaw was found in PCRE, a Perl-compatible regular expression library included within Exim. A local user could create a maliciously crafted regular expression in such as way that they could gain the privileges of the 'exim' user. The Common Vulnerabilities and Exposures project assigned the name CAN-2005-2491 to this issue. These erratum packages change Exim to use the system PCRE library instead of the internal one.
These packages also fix a minor flaw where the Exim Monitor was incorrectly computing free space on very large file systems.
Users should upgrade to these erratum packages and also ensure they have updated the system PCRE library, for which erratum packages are available seperately in RHSA-2005:761