RHSA-2003:389 - Security Advisory

Topic

Updated kernel packages are now available that fix a security
vulnerability allowing local users to gain root privileges.

Description

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 Red Hat Enterprise Linux 2.1 are advised to upgrade to these
errata packages, which contain a backported security patch that corrects
this vulnerability.

Users of Red Hat Enterprise 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.

Solution

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

To use Red Hat Network to upgrade the kernel, launch the Red Hat Update
Agent with the following command:

up2date

This will start an interactive process that will result in the appropriate
RPMs being upgraded on your system. Note that you need to select the
kernel explicitly if you are using the default configuration of up2date.

To install kernel packages manually, use "rpm -ivh <package>" and
modify system settings to boot the kernel you have installed. To
do this, edit /boot/grub/grub.conf and change the default entry to
"default=0" (or, if you have chosen to use LILO as your boot loader,
edit /etc/lilo.conf and run lilo)

Do not use "rpm -Uvh" as that will remove your running kernel binaries
from your system. You may use "rpm -e" to remove old kernels after
determining that the new kernel functions properly on your system.

Affected Products

• Red Hat Enterprise Linux Server 2 i386
• Red Hat Enterprise Linux Workstation 2 i386

Fixes

• BZ - 111240 - CAN-2003-0961 local privilege escalation via do_brk()

CVEs

• CVE-2003-0961

References

(none)