CVE-2022-40133 in Linux
Summary
by MITRE • 09/09/2022
A use-after-free(UAF) vulnerability was found in function 'vmw_execbuf_tie_context' in drivers/gpu/vmxgfx/vmxgfx_execbuf.c in Linux kernel's vmwgfx driver with device file '/dev/dri/renderD128 (or Dxxx)'. This flaw allows a local attacker with a user account on the system to gain privilege, causing a denial of service(DoS).
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Analysis
by VulDB Data Team • 10/17/2025
The vulnerability CVE-2022-40133 represents a critical use-after-free condition within the vmwgfx graphics driver component of the Linux kernel. This flaw exists specifically in the vmw_execbuf_tie_context function located in drivers/gpu/vmxgfx/vmxgfx_execbuf.c, affecting systems utilizing the vmwgfx driver with device files such as /dev/dri/renderD128 or similar render device identifiers. The vmwgfx driver serves as the graphics subsystem for VMware virtual machines, providing hardware acceleration capabilities for virtualized graphics operations. This particular vulnerability arises from improper memory management practices where freed memory locations are accessed after being deallocated, creating potential exploitation vectors for malicious actors.
The technical implementation of this use-after-free vulnerability occurs when the vmw_execbuf_tie_context function handles graphics command buffer execution within the virtualized graphics environment. When processing certain graphics operations, the driver fails to properly manage reference counts or memory pointers, leading to scenarios where memory allocated to graphics contexts becomes freed while still referenced by subsequent operations. This memory corruption pattern allows an attacker to manipulate the freed memory space, potentially executing arbitrary code with elevated privileges. The vulnerability specifically impacts the graphics subsystem's command buffer processing, where context tying operations create conditions conducive to memory management failures. According to CWE-416, this represents a classic use-after-free scenario where memory is accessed after it has been freed, violating fundamental memory safety principles.
The operational impact of CVE-2022-40133 extends beyond simple denial of service to encompass potential privilege escalation capabilities within the virtualized environment. Local attackers with standard user accounts can exploit this vulnerability to execute malicious code with kernel-level privileges, effectively bypassing standard user permissions and gaining control over the underlying graphics subsystem. This escalation path represents a significant security risk for virtualized environments where multiple users share the same physical host, as successful exploitation could lead to complete system compromise. The vulnerability's exploitation typically results in system instability, graphics rendering failures, and in severe cases, complete system crashes or unauthorized access to sensitive system resources. The impact is particularly concerning in cloud computing environments and virtual desktop infrastructures where vmwgfx drivers are extensively utilized.
Mitigation strategies for CVE-2022-40133 should prioritize immediate patch deployment from kernel vendors, as the vulnerability directly affects the core graphics subsystem of Linux kernel versions containing the vmwgfx driver. System administrators must ensure all virtualized environments utilizing VMware graphics drivers receive the appropriate kernel updates addressing this specific memory management flaw. Additionally, implementing proper access controls and limiting user privileges within virtualized environments can reduce the attack surface. Monitoring for unusual graphics processing patterns and memory allocation behaviors can help detect potential exploitation attempts. Organizations should also consider implementing runtime protections and kernel hardening measures such as stack canaries and address space layout randomization to make exploitation more difficult. The vulnerability aligns with ATT&CK technique T1068 which focuses on exploiting vulnerabilities in legitimate programs to gain system access, and T1059 which encompasses command and scripting interpreter usage for privilege escalation. Regular security assessments and kernel vulnerability scanning should be conducted to identify similar memory corruption issues within the graphics driver stack and other kernel subsystems.