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 172/2015
Buy this issue as a PDF
News
-
Old Vulnerabilities Are Kept Alive Through Bad Configuration
HP's annual Cyber Risk report offers a bleak look at the state of IT.
-
Linus Torvalds Announces Linux 4.0
But what do the big numbers really mean?
-
Microsoft Frees CoreCLR
.NET Core execution engine is the basis for cross-platform .NET implementations.
-
New Trojan Attacks Linux Servers
The Xnote trojan hides itself on the target system and will launch a variety of attacks on command.
-
Cisco Releases Annual Security Report
Spammers go low-volume, and 90% of IE browsers are unpatched.
-
Zero Day Exploits Target Flash
Adobe scrambles to release patches for vulnerable Flash Player.
-
Intel Unveils Compute Stick
Four-inch-long computer on a stick lets you boot a full Linux system from any HDMI display device.
-
Obama Proposes Personal Data Notification Law
New statute would require companies to report break-ins to consumers.
-
TGXf Project Warns of File Transfer through Screen Pixels
Weird data transfer technique avoids all standard security measures.
-
Industry Giants Announce a Fix for the Password Mess
FIDO alliance declares the beginning of the end for old-style login authentication.