Secunia

A vulnerability has been reported in various Cisco products, which can be exploited by malicious people to cause a DoS (Denial of Service).

The vulnerability is caused due to errors in the processing of IKEv1 Phase 1 protocol exchange messages. This can be exploited to cause a DoS via specially crafted IKE packets.

The vulnerability has been reported in the following products.
* Cisco IOS versions based on 12.2SXD, 12.3T, 12.4 and 12.4T
* Cisco PIX Firewall versions up to but not including 6.3(5)
* Cisco PIX Firewall/ASA versions up to but not including 7.0.1.4
* Cisco Firewall Services Module (FWSM) versions up to but not including 2.3(3)
* Cisco VPN 3000 Series Concentrators versions up to but not including 4.1(7)H and 4.7(2)B
* Cisco MDS Series SanOS versions up to but not including 2.1(2)

Note: For Cisco IOS, only images that contain the Crypto Feature Set are vulnerable.

Solution
See patch matrix in vendor advisory for information about fixes.
Further details available in Customer Area

Provided and/or discovered by
Oulu University Secure Programming Group (OUSPG).

Changelog
Further details available in Customer Area

Original Advisory
Cisco:
http://www.cisco.com/warp/public/707/cisco-sa-20051114-ipsec.shtml

NISCC:
http://www.uniras.gov.uk/niscc/docs/br-20051114-01013.html?lang=en

University of Oulu
http://www.ee.oulu.fi/research/ouspg/protos/testing/c09/isakmp/

Other references
Further details available in Customer Area

Deep Links
Links available in Customer Area