Irssi before 1.0.8, 1.1.x before 1.1.3, and 1.2.x before 1.2.1, when SASL is enabled, has a use after free when sending SASL login to the server.

An issue was discovered in Irssi before 1.0.7 and 1.1.x before 1.1.1. There is a use-after-free when SASL messages are received in an unexpected order.

An issue was discovered in Irssi before 1.0.7 and 1.1.x before 1.1.1. There is a use-after-free when a server is disconnected during netsplits. NOTE: this issue exists because of an incomplete fix for CVE-2017-7191.

An issue was discovered in Irssi before 1.0.7 and 1.1.x before 1.1.1. A NULL pointer dereference occurs for an "empty" nick.

An issue was discovered in Irssi before 1.0.7 and 1.1.x before 1.1.1. When the number of windows exceeds the available space, a crash due to a NULL pointer dereference would occur.

An issue was discovered in Irssi before 1.0.7 and 1.1.x before 1.1.1. Certain nick names could result in out-of-bounds access when printing theme strings.

The netjoin processing in Irssi 1.x before 1.0.2 allows attackers to cause a denial of service (use-after-free) and possibly execute arbitrary code via unspecified vectors.

Irssi before 0.8.21 allows remote attackers to cause a denial of service (out-of-bounds read and crash) via a string containing a formatting sequence (%[) without a closing bracket (]).

The nickcmp function in Irssi before 0.8.21 allows remote attackers to cause a denial of service (NULL pointer dereference and crash) via a message without a nick.

Irssi 0.8.18 before 0.8.21 allows remote attackers to cause a denial of service (out-of-bounds read and crash) via vectors involving strings that are not UTF8.

Use-after-free vulnerability in Irssi before 0.8.21 allows remote attackers to cause a denial of service (crash) via an invalid nick message.

Irssi 0.8.17 before 0.8.21 allows remote attackers to cause a denial of service (out-of-bounds read and crash) via a crafted ANSI x8 color code.

The formatsendtogui function in formats.c for irssi before 0.8.9 allows remote IRC users to cause a denial of service (crash).

irssi IRC client 0.8.4, when downloaded after 14-March-2002, could contain a backdoor in the configuration file, which allows remote attackers to access the system.

The buf.pl script before 2.20 in Irssi before 0.8.20 uses weak permissions for the scrollbuffer dump file created between upgrades, which might allow local users to obtain sensitive information from private chat conversations by reading the file.

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.

Irssi 1.3.x and 1.4.x before 1.4.4 has a use-after-free because of use of a stale special collector reference. This occurs when printing of a non-formatted line is concurrent with printing of a formatted line.

Irssi 1.1.x before 1.1.2 has a use after free when hidden lines are expired from the scroll buffer.

Irssi 1.2.x before 1.2.2 has a use-after-free if the IRC server sends a double CAP.

IRC client irssi in irssi-text before 0.8.4 allows remote attackers to cause a denial of service (crash) via an IRC channel that has a long topic followed by a certain string, possibly triggering a buffer overflow.

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.

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.

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.

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.

Off-by-one error in the eventwallops 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.

The formatsendtogui 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.

The unformat24bitcolor 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.

In Irssi before 1.0.5, certain incorrectly formatted DCC CTCP messages could cause a NULL pointer dereference. This is a separate, but similar, issue relative to CVE-2017-9468.