CVE-2022-46342 in X11 Server
Summary
by MITRE • 12/15/2022
A vulnerability was found in X.Org. This security flaw occurs because the handler for the XvdiSelectVideoNotify request may write to memory after it has been freed. This issue can lead to local privileges elevation on systems where the X se
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Analysis
by VulDB Data Team • 11/15/2024
The vulnerability identified as CVE-2022-46342 resides within the X.Org server implementation, specifically within the XvdiSelectVideoNotify request handler. This flaw represents a classic use-after-free condition that arises when the system attempts to write to memory that has already been deallocated. The X.Org server serves as the foundational graphics server for numerous Unix-like operating systems including linux distributions, making this vulnerability particularly concerning for desktop and workstation environments where graphical interfaces are prevalent. The issue manifests when the XvdiSelectVideoNotify request is processed, indicating that the vulnerability is specifically tied to video display interface functionality within the X Window System architecture.
The technical exploitation of this vulnerability stems from improper memory management practices within the X.Org server's request handling code. When processing the XvdiSelectVideoNotify request, the system allocates memory for certain data structures and subsequently frees this memory while the application continues to reference it. This creates a scenario where an attacker can potentially manipulate the freed memory location to execute arbitrary code or escalate privileges. The flaw falls under the CWE-416 category of Use After Free conditions, which are well-documented in the Common Weakness Enumeration catalog and represent one of the most prevalent classes of memory corruption vulnerabilities. The vulnerability specifically targets the X Window System's video display interface subsystem, which is integral to how graphical applications interact with the underlying display server.
From an operational perspective, this vulnerability presents a significant risk for local privilege escalation attacks, particularly in environments where users have the ability to interact with the X Window System. The attack vector requires local access to the system since the vulnerability is triggered through X protocol requests that are typically processed by the display server itself. Systems where the X server runs with elevated privileges or where local users have access to X applications that can send malicious requests are particularly vulnerable. The impact extends beyond simple privilege escalation to potentially allow for complete system compromise, as the attacker could leverage this vulnerability to gain root access or elevate to other privileged accounts. This vulnerability directly maps to ATT&CK technique T1068 which involves exploiting local privileges to gain higher-level access, and T1059 which encompasses the execution of code through legitimate system processes.
The mitigation strategies for CVE-2022-46342 primarily involve applying the vendor-provided patches and updates to the X.Org server implementation. System administrators should prioritize patching affected systems, particularly in environments where local users might have access to X applications that could potentially be exploited. Additionally, implementing proper access controls and restricting local access to graphical environments can serve as a temporary workaround while patches are deployed. Monitoring for suspicious X protocol activity and implementing security measures such as mandatory access controls or sandboxing of X applications can further reduce the attack surface. Organizations should also consider disabling unnecessary X server extensions and features that might not be required for their specific use cases. The vulnerability demonstrates the critical importance of proper memory management in server applications and highlights the need for thorough code reviews and security testing of core system components that handle user input and network requests.