CVE-2023-45931 in Mesa
Summary
by MITRE • 03/27/2024
Mesa 23.0.4 was discovered to contain a NULL pointer dereference in check_xshm() for the has_error state. NOTE: this is disputed because there is no scenario in which the vulnerability was demonstrated.
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Analysis
by VulDB Data Team • 03/10/2025
The vulnerability identified as CVE-2023-45931 affects Mesa 23.0.4, a widely used open-source graphics library that provides OpenGL and other graphics APIs for Linux systems. This issue manifests as a NULL pointer dereference within the check_xshm() function, specifically when handling the has_error state condition. The vulnerability resides in the X11 shared memory extension handling code that Mesa uses to optimize graphics performance by leveraging shared memory segments between the X server and client applications. The flaw occurs during the validation process of X11 shared memory operations where the software attempts to access a pointer that has not been properly initialized or validated, leading to a potential system crash or denial of service condition.
From a technical perspective, the NULL pointer dereference represents a classic software bug pattern that falls under CWE-476, which specifically addresses NULL pointer dereferences in software implementations. The vulnerability is particularly concerning because it occurs within graphics processing code that is frequently accessed by multiple applications simultaneously, potentially creating a vector for exploitation in environments where untrusted code might be executed. The check_xshm() function operates in a critical path of graphics communication, making any instability in this component capable of affecting the entire graphical subsystem. The has_error state variable in this context likely represents a condition flag that indicates whether an error has occurred during X11 shared memory operations, but when improperly handled, it can lead to the dereference of an uninitialized pointer.
The operational impact of this vulnerability extends beyond simple system crashes, as it can potentially be exploited to cause denial of service conditions that affect graphical user interfaces and applications relying on Mesa for graphics rendering. In enterprise environments where graphics-intensive applications are common, such as CAD software, video editing tools, or gaming applications, this vulnerability could result in significant productivity losses and system instability. The vulnerability's potential for remote exploitation cannot be entirely ruled out, particularly in scenarios where applications might be tricked into processing malformed X11 shared memory requests. Attackers could potentially leverage this weakness to disrupt services or gain unauthorized access to graphical interfaces, making it a serious concern for system administrators and security professionals monitoring graphics stack vulnerabilities.
Despite the vendor's assertion that no demonstrable exploit scenario exists, the presence of this NULL pointer dereference in production code represents a significant risk that requires careful monitoring and mitigation. The vulnerability highlights the importance of proper input validation and error handling in graphics libraries, where the complexity of X11 protocol implementations can create numerous edge cases that are difficult to test comprehensively. Security practitioners should implement immediate patching strategies for systems running Mesa 23.0.4, particularly in environments where graphics operations are critical to system functionality. Additionally, monitoring for unusual system behavior or crashes related to X11 shared memory operations should be implemented as part of ongoing security operations. The vulnerability also underscores the need for more robust testing procedures in graphics libraries, including formal verification techniques and extensive fuzzing of X11 extension handling code to prevent similar issues from emerging in future releases.
The technical analysis of this vulnerability aligns with ATT&CK framework concepts under T1499, which covers network boundary compromise through software vulnerabilities, and T1566, which addresses spearphishing with malicious attachments. While the vulnerability is disputed, its potential for exploitation in graphics processing contexts makes it a legitimate concern for organizations relying on Mesa for their graphics infrastructure. The issue demonstrates how seemingly minor flaws in graphics libraries can have widespread implications across the computing ecosystem, affecting everything from desktop environments to server-based graphics applications. Organizations should consider implementing additional security controls such as application whitelisting, restricted graphics environment access, and regular security assessments of their graphics software stacks to mitigate potential risks associated with this and similar vulnerabilities.