Ubuntu Update for fetchmail vulnerabilities USN-520-1

Ubuntu Update for Linux kernel vulnerabilities USN-520-1
Please Install the Updated Packages.
Gaetan Leurent discovered a vulnerability in the APOP protocol based on MD5 collisions. As fetchmail supports the APOP protocol, this vulnerability can be used by attackers to discover a portion of the APOP user's authentication credentials. (CVE-2007-1558) Earl Chew discovered that fetchmail can be made to de-reference a NULL pointer when contacting SMTP servers. This vulnerability can be used by attackers who control the SMTP server to crash fetchmail and cause a denial of service. (CVE-2007-4565)
fetchmail vulnerabilities on Ubuntu 6.06 LTS , Ubuntu 6.10 , Ubuntu 7.04