isc-dhcp - denial of service

Several security vulnerabilities affecting ISC dhcpd, a server for
automatic IP address assignment, have been discovered. Additionally, the
latest security update for isc-dhcp, DSA-2516-1,
did not properly apply the patches for
CVE-2012-3571
and
CVE-2012-3954.
This has been addressed
in this additional update.

• CVE-2011-4539
  BlueCat Networks discovered that it is possible to crash DHCP servers
  configured to evaluate requests with regular expressions via crafted
  DHCP request packets.
• CVE-2012-3571
  Markus Hietava of the Codenomicon CROSS project discovered that it is
  possible to force the server to enter an infinite loop via messages with
  malformed client identifiers.
• CVE-2012-3954
  Glen Eustace discovered that DHCP servers running in DHCPv6 mode
  and possibly DHCPv4 mode suffer of memory leaks while processing messages.
  An attacker can use this flaw to exhaust resources and perform denial
  of service attacks.

For the stable distribution (squeeze), this problem has been fixed in
version 4.1.1-P1-15+squeeze6.

For the testing (wheezy) and unstable (sid) distributions, this problem
will be fixed soon.

We recommend that you upgrade your isc-dhcp packages.