source: https://www.securityfocus.com/bid/4419/info

talkd is a client-server application shipped with many Unix and Linux variants that is used for communication between users locally or remotely.

talkd does not perform adequate validation of users making talk requests. As a result, it is possible for an attacker to spoof users during a talk session.

This problem is exploitable remotely or locally and may aid an attacker in social engineering attacks.

A malicious version of the NetBSD talkd component was used to exploit this issue, so it can be assumed that NetBSD is affected by this issue. However, talkd ships as a core component for a number of Linux and Unix variants and is independently maintained by the various distributions, so it is highly probable that many other operating systems are affected by this vulnerability. 

https://github.com/offensive-security/exploitdb-bin-sploits/raw/master/bin-sploits/21364.tar.gz