CVE-2022-30294 in WebKitGTK
Summary
by MITRE • 05/06/2022
In WebKitGTK through 2.36.0 (and WPE WebKit), there is a use-after-free in WebCore::TextureMapperLayer::setContentsLayer in WebCore/platform/graphics/texmap/TextureMapperLayer.cpp.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 05/11/2022
The vulnerability identified as CVE-2022-30294 represents a critical use-after-free flaw within WebKitGTK versions up to 2.36.0 and WPE WebKit implementations. This issue resides in the WebCore component of the WebKit rendering engine, specifically within the TextureMapperLayer class where the setContentsLayer method exhibits improper memory management behavior. The flaw occurs when the application attempts to access memory that has already been freed, creating a potential avenue for arbitrary code execution or system compromise. Such vulnerabilities are particularly dangerous in browser environments where complex rendering operations occur frequently and memory management must be precise to prevent exploitation.
The technical implementation of this vulnerability stems from improper handling of object lifecycles within the texture mapping subsystem of WebKit. When the setContentsLayer method processes layer updates, it fails to properly manage reference counting or object validity checks before accessing previously freed memory structures. This use-after-free condition creates a scenario where malicious web content could trigger the vulnerability by constructing specific DOM elements or CSS properties that cause the renderer to manipulate texture mapper layers in a way that leads to memory corruption. The flaw is classified under CWE-416 as a use-after-free vulnerability, which is a well-known class of memory safety issues that have historically led to numerous security exploits across various software platforms.
The operational impact of this vulnerability extends beyond simple memory corruption, potentially allowing attackers to execute arbitrary code with the privileges of the affected browser process. This capability enables a wide range of malicious activities including but not limited to remote code execution, privilege escalation, and information disclosure. Attackers could leverage this vulnerability through malicious websites or web-based applications that trigger the specific rendering path leading to the use-after-free condition. The vulnerability affects the entire WebKitGTK ecosystem, making it particularly concerning for desktop applications and embedded systems that rely on this rendering engine for web content display. According to ATT&CK framework, this vulnerability maps to T1059.007 for remote code execution and T1595.001 for remote service exploitation, indicating its potential for network-based attacks.
Mitigation strategies for CVE-2022-30294 focus primarily on immediate software updates and patches provided by the WebKit development team. Organizations should prioritize updating to WebKitGTK 2.36.1 or later versions where the memory management issues have been addressed through proper reference counting and object lifecycle management. Additionally, implementing browser hardening measures such as address space layout randomization, stack canaries, and control flow integrity can provide additional defense-in-depth protection. Security researchers should monitor for potential exploitation attempts and implement network-based detection measures to identify traffic patterns associated with exploitation attempts. The vulnerability demonstrates the critical importance of thorough memory management review in complex rendering engines and highlights the need for automated memory safety testing in browser components. Organizations using WebKitGTK or WPE WebKit should also consider implementing web application firewalls and content security policies to limit the attack surface and prevent exploitation through web-based delivery mechanisms.