Executive brief
A vulnerability exists in the BSD Telnet client when using Kerberos 4 authentication and session encryption. This flaw allows an attacker who can monitor network traffic to bypass the intended encryption and read the contents of the communication. This could lead to the exposure of sensitive information transmitted during the remote login session.
Technical details
The BSD Telnet client contains a flaw in its implementation of session encryption when paired with Kerberos 4 authentication. Due to an error in how encryption keys are handled or negotiated, the session encryption can be compromised by an attacker with the ability to capture network packets (sniffing). This allows the attacker to decrypt the supposedly secure communication stream. The vulnerability is exploited over the network without requiring prior authentication, though it requires the attacker to be in a position to intercept traffic. Patches were released by various vendors following the CERT advisory in 1995.
Affected products
- BSD Telnet client All versions using Kerberos 4 and encryption prior to March 1995
Timeline
- 1995-03-03: advisory: Initial NVD publication and CERT advisory CA-1995-03 released