In Irssi before 1.0.3, when receiving certain incorrectly quoted DCC files, it tries to find the terminating quote one byte before the allocated memory. Thus, remote attackers might be able to cause a crash.
https://irssi.org/security/irssi_sa_2017_06.txt
http://www.securitytracker.com/id/1038621
http://www.securityfocus.com/bid/99043