Ubuntu 4.10 / 5.04 : squid vulnerability (USN-129-1)
Medium Nessus Plugin ID 20519
SynopsisThe remote Ubuntu host is missing one or more security-related patches.
DescriptionIt was discovered that Squid did not verify the validity of DNS server responses. When Squid is started, it opens a DNS client UDP port whose number is randomly assigned by the operating system. Unless your network firewall is configured to accept DNS responses only from known good nameservers, this vulnerability allowed users within the local network to inject arbitrary DNS responses into Squid ('DNS spoofing').
This could be used to present different web pages to users from those they actually requested.
Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
SolutionUpdate the affected packages.