Secunia Security Advisory – Nortel Networks has acknowledged an old vulnerability in Communication Server 1000 (CS1000), which can be exploited by malicious people to cause a DoS (Denial of Service).
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/38330/sa15826.txt
Source: https://packetstormsecurity.com/files/38330/Secunia-Security-Advisory-15826.html