[linux-security] DoS and local root exploits in Linux kernel

[Martin Siegert <siegert@sfu.ca>]

Topic
=====
DoS attack possible because of vulnerability in Linux kernel
flaw in kernel allows local priviledge escalation

Problem Description
===================
The route cache implementation in Linux 2.4, and the Netfilter IP
conntrack module, allows remote attackers to cause a denial of service
(CPU consumption) via packets with forged source addresses that cause a
large number of hash table collisions related to the PREROUTING chain.

A flaw has been found in the "ioperm" system call, which fails to properly
restrict privileges. This flaw can allow an unprivileged local user to
gain read and write access to I/O ports on the system.

Affected Versions
=================
all 2.4.x versions with x <= 20 (which is the newest)

Solution
========
upgrade to patched version for your distribution
(both problems have been fixed in 2.4.21-rc4; 2.4.21 will probably be
released within the next few weeks)

RedHat 7.1
----------