CVE-2004-0093 in X11r6
Summary
by MITRE
XFree86 4.1.0 allows remote attackers to cause a denial of service and possibly execute arbitrary code via an out-of-bounds array index when using the GLX extension and Direct Rendering Infrastructure (DRI).
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 06/29/2021
The vulnerability identified as CVE-2004-0093 represents a critical security flaw in XFree86 version 4.1.0 that affects the Graphics Library eXtension (GLX) and Direct Rendering Infrastructure (DRI) components. This vulnerability stems from improper input validation within the graphics subsystem, specifically when processing array indices during GLX operations with DRI support enabled. The flaw allows remote attackers to manipulate memory access patterns through crafted malicious requests that exceed the bounds of allocated arrays, potentially leading to system instability and unauthorized code execution.
The technical implementation of this vulnerability involves a classic buffer overflow condition within the graphics processing pipeline where the GLX extension fails to properly validate array indices before accessing graphical data structures. When DRI is enabled, the graphics driver operates in a more privileged mode that allows direct hardware access, amplifying the potential impact of the out-of-bounds memory access. This particular flaw maps to CWE-129, which describes improper validation of array indices, and also aligns with CWE-787, representing out-of-bounds write operations that can occur when array bounds are not properly checked.
The operational impact of CVE-2004-0093 extends beyond simple denial of service to potentially enable remote code execution in affected systems. Attackers can exploit this vulnerability by sending specially crafted GLX protocol requests that trigger the out-of-bounds array access, which may result in memory corruption and subsequent arbitrary code execution. The vulnerability affects systems running XFree86 4.1.0 with GLX and DRI enabled, making it particularly dangerous in networked environments where graphics services are exposed to untrusted users or applications. The attack vector requires network access to the affected X server and does not require authentication, making it a significant threat to system availability and integrity.
The exploitation of this vulnerability demonstrates several characteristics consistent with the MITRE ATT&CK framework, particularly in the area of privilege escalation and execution. The flaw can be categorized under T1068, which describes the use of legitimate credentials for privilege escalation, as the DRI functionality typically requires elevated privileges to access hardware directly. Additionally, this vulnerability could be leveraged as part of a broader attack chain under T1203, involving the exploitation of software vulnerabilities to gain unauthorized access to systems. Organizations should consider implementing network segmentation to limit exposure of X servers with DRI enabled and ensure that all systems are updated to patched versions of XFree86 that address this specific array indexing issue.
Mitigation strategies for CVE-2004-0093 should include immediate deployment of security patches provided by the XFree86 project or affected vendors, as well as network-level controls to restrict access to X servers from untrusted networks. System administrators should disable DRI functionality when it is not required for specific applications, and consider implementing application whitelisting policies to prevent unauthorized graphics operations. Regular security assessments should verify that all graphics components are updated to versions that address this vulnerability, and monitoring should be implemented to detect anomalous GLX protocol behavior that might indicate exploitation attempts. The vulnerability also underscores the importance of proper input validation in graphics drivers and highlights the need for comprehensive security testing of graphics subsystems that operate with elevated privileges and direct hardware access.