A vulnerability has been reported in Nortel CS1000, which potentially can be exploited by malicious people to cause a DoS (Denial of Service).

The vulnerability is caused due to an unspecified error within the processing of packets received through certain ELAN (Embedded LAN) ports, e.g 7734/TCP, 15000/TCP, 15080/TCP, and 15000/UDP. This can potentially be exploited to disable the affected server by flooding specific ELAN ports.

The vulnerability is reported in the following products:
* Enterprise VoIP-Core-CS 1000M Chassis/Cabinet
* Enterprise VoIP-Core-CS 1000E and 1000S
* Meridian-Core-Option 11C - Chassis/Cabinet
* Meridian-Core-Option 51C, 61C, and 81C

Solution
The vendor recommends that customers restrict direct access to the ELAN from unknown devices.

Provided and/or discovered by
Daniel Stirnimann and Cyrill Brunschwiler, Compass Security Network Computing AG.

Changelog
Further details available to Secunia VIM customers

Original Advisory
Nortel:
http://www116.nortel.com/pub/repository/CLARIFY/DOCUMENT/2007/42/022871-01.pdf

Compass Security Network Computing AG:
http://www.csnc.ch/static/advisory/csnc/nortel_telephony_server_denial_of_service_v1.0.txt

Alternate/detailed remediation
Further details available in Customer Area

Deep Links
Links available to Secunia VIM customers