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.
The official irssi docker images before 1.1-alpine (Alpine specific) contain a blank password for a root user. System using the irssi docker container deployed by affected versions of the Docker image may allow an remote attacker to achieve root access with a blank password.
When using incomplete escape codes, Irssi before 1.0.6 may access data beyond the end of the string.
When using an incomplete variable argument, Irssi before 1.0.6 may access data beyond the end of the string.
When the channel topic is set without specifying a sender, Irssi before 1.0.6 may dereference a NULL pointer.
In Irssi before 1.0.6, a calculation error in the completion code could cause a heap buffer overflow when completing certain strings.
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.
In Irssi before 1.0.5, overlong nicks or targets may result in a NULL pointer dereference while splitting the message.
In certain cases, Irssi before 1.0.5 may fail to verify that a Safe channel ID is long enough, causing reads beyond the end of the string.
Irssi before 1.0.5, while waiting for the channel synchronisation, may incorrectly fail to remove destroyed channels from the query list, resulting in use-after-free conditions when updating the state later on.
Irssi before 1.0.5, when installing themes with unterminated colour formatting sequences, may access data beyond the end of the string.
An issue was discovered in Irssi before 1.0.4. While updating the internal nick list, Irssi could incorrectly use the GHashTable interface and free the nick while updating it. This would then result in use-after-free conditions on each access of the hash table.
An issue was discovered in Irssi before 1.0.4. When receiving messages with invalid time stamps, Irssi would try to dereference a NULL pointer.
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.