CVE-2023-45913 in Mesa
Summary
by MITRE • 03/27/2024
Mesa v23.0.4 was discovered to contain a NULL pointer dereference via the function dri2GetGlxDrawableFromXDrawableId(). This vulnerability is triggered when the X11 server sends an DRI2_BufferSwapComplete event unexpectedly when the application is using DRI3. NOTE: this is disputed because there is no scenario in which the vulnerability was demonstrated.
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Analysis
by VulDB Data Team • 11/07/2024
The vulnerability identified as CVE-2023-45913 affects Mesa version 23.0.4 and represents a NULL pointer dereference condition within the dri2GetGlxDrawableFromXDrawableId() function. This flaw manifests when the X11 server unexpectedly delivers a DRI2_BufferSwapComplete event while applications are operating under DRI3 protocol. The technical implementation involves a critical error in the graphics subsystem's event handling mechanism where the software attempts to access a null pointer reference during the processing of graphics buffer swap operations. The vulnerability resides in the Mesa graphics library's compatibility layer between different Direct Rendering Infrastructure protocols, specifically when transitioning between DRI2 and DRI3 contexts. This issue demonstrates a classic improper handling of inter-protocol communication scenarios where the software fails to validate the expected protocol context before executing operations that assume specific memory structures are properly initialized.
The operational impact of this vulnerability extends to graphics rendering applications that utilize the Mesa graphics library and operate in environments where both DRI2 and DRI3 protocols may be present. When triggered, the NULL pointer dereference would cause the affected application or graphics subsystem to crash, potentially leading to denial of service conditions for users engaged in graphics-intensive tasks. The vulnerability's exploitation requires specific conditions involving X11 server behavior and application protocol usage patterns, making it less straightforward to reproduce in typical environments. From a cybersecurity perspective, this vulnerability represents a potential vector for denial of service attacks targeting graphics applications and could impact desktop environments, virtualized graphics sessions, or server-based graphics rendering systems. The flaw's classification aligns with CWE-476 which addresses NULL pointer dereference conditions, and could be mapped to ATT&CK technique T1499.3 for denial of service through application or system manipulation.
The disputed nature of this vulnerability stems from the lack of demonstrated exploit scenarios that would reliably trigger the NULL pointer dereference condition. Security researchers have questioned whether the described circumstances can actually occur in real-world deployments, as the specific combination of X11 server behavior and application protocol usage required for exploitation appears to be highly contrived or non-existent in typical usage patterns. This uncertainty regarding exploitability makes the vulnerability less immediately concerning from a threat perspective, though the underlying code structure still represents a potential risk. The Mesa project's maintainers and security teams have expressed skepticism about the practical exploitability of this particular flaw, suggesting that either the conditions for exploitation are extremely rare or that the vulnerability may not be as significant as initially reported. The lack of concrete demonstration cases means that while the code analysis reveals a potential issue, the actual risk to deployed systems remains uncertain and requires further validation through real-world testing scenarios.