Vulnerability Discovered in X Font Server
Two protocol handlers give attackers the ability to inject malicious code into X Font Server (XFS). Linux systems are only vulnerable to local attacks. The X Font Server is not accessible over networks by default.
The bug (CVE-2007-4568) in the handler for QueryXBitmap and QueryXExtents protocol requests can trigger integer overflows. In both protocols this triggers a call to the "build_range()" function which expects a 32 bit integer value with the request, and calculates the dynamic memory size. The calculation can overflow causing incorrect memory allocation. This results in a heap overflow. A second vulnerability affects the "swap_char2b()". Calling the function gives attackers the ability to store an arbitrary number of values on the heap. A successful exploit would give an attacker the ability to execute arbitrary code.
Security experts with Idefense tested a Solaris system. Solaris calls XFS by default on booting, and sets up the X Server to listen on port 7100, which would thus open up a remote attack vector. Idefense discovered the vulnerability in XFS version X11R7.2-1.0.4, although earlier versions may also be affected.
The X.org-Team has fixed the issue in the new XFS 1.0.5 Version. A patch is available for for version 1.0.4 (X11R7.3).
Issue 259/2022
Buy this issue as a PDF
News
-
Titan Linux is a New KDE Linux Based on Debian Stable
Titan Linux is a new Debian-based Linux distribution that features the KDE Plasma desktop with a focus on usability and performance.
-
Danielle Foré Has an Update for elementary OS 7
Now that Ubuntu 22.04 has been released, the team behind elementary OS is preparing for the upcoming 7.0 release.
-
Linux New Media Launches Open Source JobHub
New job website focuses on connecting technical and non-technical professionals with organizations in open source.
-
Ubuntu Cinnamon 22.04 Now Available
Ubuntu Cinnamon 22.04 has been released with all the additions from upstream as well as other features and improvements.
-
Pop!_OS 22.04 Has Officially Been Released
From the makers of some of the finest Linux-powered desktop and laptop computers on the market comes the latest version of their Ubuntu-based distribution, Pop!_OS 22.04.
-
Star Labs Unveils a New Small Format Linux PC
The Byte Mk I is an AMD-powered mini Linux PC with Coreboot support and plenty of power.
-
MX Linux Verison 21.1 “Wildflower” Now Available
The latest release of the systemd-less MX Linux is now ready for public consumption.
-
Microsoft Expands Their Windows Subsystem for Linux Offerings With AlmaLinux
Anyone who works with Windows Subsystem for Linux (WSL) will now find a new addition to the available distributions, one that’s become the front-runner replacement for CentOS.
-
Debian 11.3 Released wIth Numerous Bug and Security Fixes
The latest point release for Debian Bullseye is now available with some very important updates.
-
The First Alpha of Asahi Linux is Available
Asahi Linux is the first distribution to fully support Apple Silicon and is now available for testing.