Secunia Security Advisory – Citrix has acknowledged a vulnerability in NetScaler, which can be exploited by malicious people to poison the DNS cache.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/68505/sa31221.txt
Source: https://packetstormsecurity.com/files/68505/Secunia-Security-Advisory-31221.html

