The linux kernel packages are affected (linux-image*, linux-patch*)
For more details, please visit the referenced security advisories.
Solution: The problem can be corrected by upgrading the affected package to version 2.6.8.1-16.24 (for Ubuntu 4.10), or 2.6.10-34.7 (for Ubuntu 5.04). After a standard system upgrade you need to reboot your computer to effect the necessary changes. http://www.securityspace.com/smysecure/catid.html?in=USN-199-1