Arch Linux Security Advisory ASA-201701-14
=========================================
Severity: High
Date    : 2017-01-11
CVE-ID  : CVE-2017-5193 CVE-2017-5194 CVE-2017-5195 CVE-2017-5196
Package : irssi
Type    : multiple issues
Remote  : Yes
Link    : https://security.archlinux.org/AVG-127

Summary
======
The package irssi before version 0.8.21-1 is vulnerable to multiple
issues including arbitrary code execution and denial of service.

Resolution
=========
Upgrade to 0.8.21-1.

# pacman -Syu "irssi>=0.8.21-1"

The problems have been fixed upstream in version 0.8.21.

Workaround
=========
None.

Description
==========
- CVE-2017-5193 (denial of service)

A NULL pointer dereference has been discovered in the nickcmp function
leading to application crash.

- CVE-2017-5194 (arbitrary code execution)

A use after free vulnerability has been discovered when receiving an
invalid nick message potentially leading to arbitrary code execution.

- CVE-2017-5195 (denial of service)

An out of bounds read has been discovered in certain incomplete control
codes leading to application crash.

- CVE-2017-5196 (denial of service)

An out of bounds read has been discovered in certain incomplete
character sequences leading to application crash.

Impact
=====
A remote attacker is able to crash the application or execute arbitrary
code on the affected host.

References
=========
https://irssi.org/security/irssi_sa_2017_01.txt
https://www.openwall.com/lists/oss-security/2017/01/05/2
https://github.com/irssi/irssi/commit/6c6c42e3d1b49d90aacc0b67f8540471cae02a1d
https://security.archlinux.org/CVE-2017-5193
https://security.archlinux.org/CVE-2017-5194
https://security.archlinux.org/CVE-2017-5195
https://security.archlinux.org/CVE-2017-5196