The unformat_24bit_color function in the format parsing code in Irssi before 0.8.20, when compiled with true-color enabled, allows remote attackers to cause a denial of service (heap corruption and crash) via an incomplete 24bit color code.

The format_send_to_gui function in the format parsing code in Irssi before 0.8.20 allows remote attackers to cause a denial of service (heap corruption and crash) via vectors involving the length of a string.

core/nicklist.c in Irssi before 0.8.15 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via vectors related to an attempted fuzzy nick match at the instant that a victim leaves a channel.

Irssi before 0.8.15, when SSL is used, does not verify that the server hostname matches a domain name in the subject's Common Name (CN) field or a Subject Alternative Name field of the X.509 certificate, which allows man-in-the-middle attackers to spoof IRC servers via an arbitrary certificate.

Off-by-one error in the event_wallops function in fe-common/irc/fe-events.c in irssi 0.8.13 allows remote IRC servers to cause a denial of service (crash) via an empty command, which triggers a one-byte buffer under-read and a one-byte buffer underflow.

Multiple CRLF injection vulnerabilities in (1) xmms-thing 1.0, (2) XMMS Remote Control Script 1.07, (3) Disrok 1.0, (4) a2x 0.0.1, (5) Another xmms-info script 1.0, (6) XChat-XMMS 0.8.1, and other unspecified scripts for XChat allow user-assisted remote attackers to execute arbitrary IRC commands via CRLF sequences in the name of the song in a .mp3 file.

Multiple CRLF injection vulnerabilities in the (1) now-playing.rb and (2) xmms.pl 1.1 scripts for WeeChat allow user-assisted remote attackers to execute arbitrary IRC commands via CRLF sequences in the name of the song in a .mp3 file.

CRLF injection vulnerability in the xmms.bx 1.0 script for BitchX allows user-assisted remote attackers to execute arbitrary IRC commands via CRLF sequences in the name of the song in a .mp3 file.

Multiple CRLF injection vulnerabilities in (1) ixmmsa.pl 0.3, (2) l33tmusic.pl 2.00, (3) mpg123.pl 0.01, (4) ogg123.pl 0.01, (5) xmms.pl 2.0, (6) xmms2.pl 1.1.3, and (7) xmmsinfo.pl 1.1.1.1 scripts for irssi before 0.8.11 allow user-assisted remote attackers to execute arbitrary IRC commands via CRLF sequences in the name of the song in a .mp3 file.

The DCC ACCEPT command handler in irssi before 0.8.9+0.8.10rc5-0ubuntu4.1 in Ubuntu Linux, and possibly other distributions, allows remote attackers to cause a denial of service (application crash) via certain crafted arguments in a DCC command.