VanDyke Software Inc. Information for VU#978316
Vulnerability in OpenSSH daemon (sshd)
VShell connection filters are vulnerable to this type of attack if hostname of domain name based filters are used in any of the connection filters.
VShell starts with the IP address provided by the TCP/IP protocol stack for the connection.
If there are no name based filters in the connection filter list, it simply uses this address to do filtering-- no name resolution is performed, and therefore, no vulnerability exists.
If there are name based filters in the connection filter list, VShell must discover all the hostnames associated with the connection IP. It does this through DNS, which is subject to trivial spoofing.
It is recommended that our customers _not_ use hostname or domain name based filtering, but rather, use IP and netmask based filtering.
The vendor has not provided us with any further information regarding this vulnerability.
The CERT/CC has no additional comments at this time.
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