Arch Linux alert ASA-202105-12 (libx11)

From:
             
 
Jonas Witschel via arch-security <arch-security@lists.archlinux.org>
To:
             
 
arch-security@lists.archlinux.org
Subject:
             
 
[ASA-202105-12] libx11: insufficient validation
Date:
             
 
Thu, 20 May 2021 20:06:05 +0200
Message-ID:
             
 
<20210520180605.gven5gmm3bbx7vti@archlinux.org>
Cc:
             
 
Jonas Witschel <diabonas@archlinux.org>
Arch Linux Security Advisory ASA-202105-12
==========================================

Severity: High
Date    : 2021-05-19
CVE-ID  : CVE-2021-31535
Package : libx11
Type    : insufficient validation
Remote  : No
Link    : https://security.archlinux.org/AVG-1968

Summary
=======

The package libx11 before version 1.7.1-1 is vulnerable to insufficient
validation.

Resolution
==========

Upgrade to 1.7.1-1.

# pacman -Syu "libx11>=1.7.1-1"

The problem has been fixed upstream in version 1.7.1.

Workaround
==========

None.

Description
===========

A security issue has been found in libx11 before version 1.7.1.
XLookupColor() and other X libraries function lack proper validation of
the length of their string parameters. If those parameters can be
controlled by an external application (for instance a color name that
can be emitted via a terminal control sequence) it can lead to the
emission of extra X protocol requests to the X server.

Impact
======

An attacker could emit arbitrary X protocol requests to the X server
through crafted string parameters.

References
==========

https://unparalleled.eu/publications/2021/advisory-unpar-...
https://unparalleled.eu/blog/2021/20210518-using-xterm-to...
https://gitlab.freedesktop.org/xorg/lib/libx11/-/commit/8...
https://security.archlinux.org/CVE-2021-31535