tnef -- An attacker may be able to write to the victim's .ssh/authorized_keys file via an e-mail message

cve@mitre.org reports:

In tnef before 1.4.18, an attacker may be able to write to the victim's .ssh/authorized_keys file via an e-mail message with a crafted winmail.dat application/ms-tnef attachment, because of a heap-based buffer over-read involving strdup.

[source]