Updated kernel packages are now available that fix a security vulnerability allowing local users to gain root privileges.
The Linux kernel handles the basic functions of the operating system. A flaw in bounds checking in the do_brk() function in the Linux kernel versions 2.4.22 and previous can allow a local attacker to gain root privileges. This issue is known to be exploitable; an exploit has been seen in the wild that takes advantage of this vulnerability. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2003-0961 to this issue. All users of CentOS Linux 2.1 are advised to upgrade to these errata packages, which contain a backported security patch that corrects this vulnerability. Users of CentOS Linux 3 should upgrade to the kernel packages provided by RHBA-2003:308 (released on 30 October 2003), which already contained a patch correcting this issue.