Secunia

Gaël Delalleau has reported a weakness in Kerberos V5, which can be exploited by malicious people to gain knowledge of various information.

The problem is caused due to a design error in the Telnet client when handling the NEW-ENVIRON command. This can be exploited to gain knowledge of the session variables for a user, who has an open connection to a malicious Telnet server.

The weakness has been reported in the telnet client included in the Kerberos V5 Release 1.3.6 package. Other versions may also be affected.

Solution
The vendor is reportedly considering to release patches, which implement an option to restrict or disable the transmission of environment variables by the telnet client.

Provided and/or discovered by
Gaël Delalleau

Original Advisory
iDEFENSE:
http://www.idefense.com/application/poi/display?id=260&type=vulnerabilities

Deep Links
Links available in Customer Area