The remote Red Hat host is missing one or more security updates.
Updated kernel packages that fix one security issue, various bugs, and
add one enhancement are now available for Red Hat Enterprise Linux 5.
The Red Hat Security Response Team has rated this update as having
important security impact. A Common Vulnerability Scoring System
(CVSS) base score, which gives a detailed severity rating, is
available from the CVE link in the References section.
The kernel packages contain the Linux kernel, the core of any Linux
This update fixes the following security issue :
* A flaw in the xfrm6_tunnel_rcv() function in the Linux kernel's IPv6
implementation could lead to a use-after-free or double free flaw in
tunnel6_rcv(). A remote attacker could use this flaw to send specially
crafted packets to a target system that is using IPv6 and also has the
xfrm6_tunnel kernel module loaded, causing it to crash.
If you do not run applications that use xfrm6_tunnel, you can prevent
the xfrm6_tunnel module from being loaded by creating (as the root
user) a '/etc/modprobe.d/xfrm6_tunnel.conf' file, and adding the
following line to it :
This way, the xfrm6_tunnel module cannot be loaded accidentally. A
reboot is not necessary for this change to take effect.
This update also fixes various bugs and adds an enhancement.
Documentation for these changes will be available shortly from the
Technical Notes document linked to in the References section.
Users should upgrade to these updated packages, which contain
backported patches to correct this issue, and fix the bugs and add the
enhancement noted in the Technical Notes. The system must be rebooted
for this update to take effect.
See also :
Update the affected packages.
Risk factor :
Medium / CVSS Base Score : 5.0