CVE-2004-0106 in X11r6
Summary
by MITRE
Multiple unknown vulnerabilities in XFree86 4.1.0 to 4.3.0, related to improper handling of font files, a different set of vulnerabilities than CVE-2004-0083 and CVE-2004-0084.
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Analysis
by VulDB Data Team • 06/29/2021
The vulnerability identified as CVE-2004-0106 represents a significant security flaw within the XFree86 graphics subsystem that affected versions 4.1.0 through 4.3.0. This issue specifically pertains to the improper handling of font files within the X Window System implementation, creating potential attack vectors that could be exploited by malicious actors. The vulnerability was classified as having unknown characteristics in its original reporting, indicating that the full scope of exploitable conditions had not yet been fully understood or documented by the security community at the time of discovery.
The technical flaw manifests in the way XFree86 processes font files, particularly those with malformed or specially crafted structures that can trigger buffer overflows, memory corruption, or other memory-related issues within the graphics server. This improper handling occurs during font loading operations when the system attempts to parse and process font data without adequate validation or bounds checking. The vulnerability exists at the intersection of font rendering and memory management within the X server, where insufficient input sanitization allows attacker-controlled data to cause unexpected behavior in the underlying graphics subsystem. These issues are categorized under common weakness enumeration CWE-121, which deals with stack-based buffer overflow conditions, and CWE-125, which addresses out-of-bounds read vulnerabilities that can occur during font processing.
The operational impact of CVE-2004-0106 extends beyond simple denial of service scenarios, as the vulnerability could potentially allow for arbitrary code execution on affected systems. When exploited, the improper font file handling could enable attackers to manipulate memory contents, potentially leading to privilege escalation or complete system compromise. The attack surface is particularly concerning in multi-user environments where XFree86 serves as the primary graphics server, as local users or network-based attackers could leverage these vulnerabilities to gain unauthorized access to system resources. The vulnerability affects systems running XFree86 versions that were widely deployed in enterprise environments, making the potential impact substantial across various organizational infrastructures. This type of vulnerability aligns with attack patterns described in the mitre attack framework under techniques related to privilege escalation and code injection within graphical user interface subsystems.
Mitigation strategies for CVE-2004-0106 primarily involve immediate system updates and patches provided by the XFree86 project and affected vendors. Organizations should prioritize upgrading to patched versions of XFree86 that address the font handling vulnerabilities, particularly focusing on versions 4.3.1 and later where the specific memory handling issues have been resolved. Additionally, implementing proper font file validation mechanisms and restricting font file permissions can help reduce the attack surface. System administrators should also consider implementing network segmentation and access controls to limit exposure of X servers to untrusted networks. The vulnerability underscores the importance of proper input validation and memory management practices in graphics subsystems, aligning with security best practices that emphasize defensive programming techniques and the principle of least privilege in system design. Regular security assessments and monitoring for similar vulnerabilities in legacy graphics systems remain essential for maintaining overall system security posture.