Linux Kernel IP Stack ICMP Error Response Arbitrary Memory Information Disclosure
Medium Nessus Plugin ID 11704
SynopsisThe remote host is affected by an information disclosure vulnerability.
DescriptionThe remote host is vulnerable to an 'icmp leak' of potentially confidential data. That is, when the host generates an ICMP error packet other than 'destination unreachable', the error packet is supposed to only contain the original message or a portion of the original message.
Due to a bug in the remote TCP/IP stack, these ICMP error messages will also contain fragments of the content of the remote kernel memory.
An attacker may use this flaw to remotely sniff what is going into the host's memory, especially network packets that it sees, and obtain useful information such as POP passwords, HTTP authentication fields, and so on.
SolutionContact your vendor for a fix. If the remote host is running Linux 2.0, upgrade to Linux 2.0.40.