CVE-2021-45482 in WebKitGTK
Summary
by MITRE • 12/25/2021
In WebKitGTK before 2.32.4, there is a use-after-free in WebCore::ContainerNode::firstChild, a different vulnerability than CVE-2021-30889.
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Analysis
by VulDB Data Team • 07/10/2025
The vulnerability identified as CVE-2021-45482 affects WebKitGTK versions prior to 2.32.4 and represents a use-after-free condition within the WebCore::ContainerNode::firstChild function. This flaw resides in the core rendering engine component of WebKitGTK, which is utilized by various applications including web browsers and embedded web content viewers. The vulnerability is particularly concerning as it demonstrates a classic memory safety issue that can be exploited to execute arbitrary code or cause application crashes.
The technical implementation of this vulnerability occurs within the ContainerNode class structure where the firstChild method fails to properly manage memory references. When an application processes web content that triggers specific DOM manipulation patterns, the memory allocated for container node elements becomes freed while still being referenced by subsequent operations. This creates a window where maliciously crafted web content can cause the application to dereference freed memory, leading to unpredictable behavior and potential exploitation. The flaw differs from CVE-2021-30889, indicating distinct code paths and memory management issues within the WebKitGTK codebase.
From an operational impact perspective, this vulnerability poses significant risks to web browsing applications that utilize WebKitGTK as their rendering engine. Attackers can craft malicious web pages that, when loaded in affected applications, trigger the use-after-free condition and potentially execute remote code on the target system. The exploitation requires user interaction through visiting malicious web content, making it a typical web-based attack vector. The vulnerability affects not only standalone browsers but also applications that embed WebKitGTK for displaying web content, expanding the potential attack surface considerably.
The mitigation strategy for CVE-2021-45482 involves immediate upgrade to WebKitGTK version 2.32.4 or later, which contains the necessary patches to address the memory management issue. Organizations should prioritize patching affected systems and monitoring for any exploitation attempts. Additionally, implementing browser hardening measures such as sandboxing and memory protection mechanisms can provide additional defense layers. This vulnerability aligns with CWE-416, which describes the use-after-free condition, and can be categorized under ATT&CK technique T1203, representing exploitation of web browsers. Security teams should also consider deploying web application firewalls and content filtering solutions to block malicious content before it reaches vulnerable applications. The patching process should be carefully managed to ensure compatibility with existing applications that depend on WebKitGTK functionality, while maintaining the security posture against this and related memory corruption vulnerabilities.