Kernel: FTP iptables vulnerability in 2.4 kernel and general bug fixes

A security hole has been found that does not affect the default
configuration of Red Hat Linux, but it can affect some custom
configurations of Red Hat Linux 7.1. The bug is specific
to the Linux 2.4 kernel series. Aside from the fix, countless bugfixes
have been applied to this kernel as a result of code-audits by the
MC project of the Stanford University and others.

A vulnerability in iptables "RELATED" connection tracking has been
discovered. When using iptables to allow FTP "RELATED" connections
through the firewall, carefully constructed PORT commands can open
arbitrary holes in the firewall.

Default installations of Red Hat Linux 7.1 are not vulnerable; however
upgrading to this kernel is recommended regardless in order to benefit from
the other bug fixes in this kernel.

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

The procedure for upgrading the kernel is documented at:


http://www.redhat.com/support/docs/howto/kernel-upgrade/kernel-upgrade.html

Please read the directions for your architecture carefully before
proceeding with the kernel upgrade.

Please note that this update is also available via Red Hat Network. Many
people find this an easier way to apply updates. To use Red Hat Network,
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.

http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2001-0405
http://www.redhat.com/support/errata/RHSA-2001-052.html
http://www.redhat.com/support/docs/howto/kernel-upgrade/kernel-upgrade.html

kernel