Vigil@nce: IP Filter, ISA, DNS vulnerability with NAT
November 2008 by Vigil@nce
When the address translation is enabled on the firewall, protections which are setup to correct VIGILANCE-VUL-7937 are not efficient.
Consequences: data creation/edition
Provenance: internet server
Means of attack: no proof of concept, no attack
Ability of attacker: expert (4/4)
Confidence: confirmed by the editor (5/5)
Diffusion of the vulnerable configuration: high (3/3)
Creation date: 12/11/2008
Unix - plateform
The solution for the VIGILANCE-VUL-7937 (DNS poisoning) vulnerability requires to use random port numbers.
However, when the DNS server is protected by a firewall with address translation, the DNS server is still vulnerable if the firewall uses predictable port numbers.
Two firewalls cause this regression:
Microsoft ISA Server
Identifiers: 245206, 6726575, 6730614, VIGILANCE-VUL-8237