CVE-2023-25361 in WebKitGTK
Summary
by MITRE • 03/02/2023
A use-after-free vulnerability in WebCore::RenderLayer::setNextSibling in WebKitGTK before 2.36.8 allows attackers to execute code remotely.
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Analysis
by VulDB Data Team • 11/30/2025
This vulnerability exists within the WebKitGTK rendering engine's WebCore component specifically in the WebCore::RenderLayer::setNextSibling method. The issue represents a classic use-after-free condition that occurs when memory previously allocated to a RenderLayer object is freed but subsequently accessed by the setNextSibling function. Such memory corruption vulnerabilities typically arise from improper object lifecycle management where references to deallocated memory persist, creating opportunities for malicious code execution through memory manipulation. The vulnerability affects WebKitGTK versions prior to 2.36.8, indicating a regression or oversight in the memory management implementation that has persisted across multiple releases.
The technical exploitation of this vulnerability requires an attacker to craft malicious web content that triggers the specific code path leading to the use-after-free condition. When a web page containing crafted content is rendered, the setNextSibling function attempts to manipulate layer siblings while a RenderLayer object has already been freed from memory. This creates a scenario where the freed memory can be reallocated and manipulated by the attacker to overwrite critical data structures or function pointers, ultimately enabling arbitrary code execution. The vulnerability is particularly dangerous in web browser contexts because it can be triggered remotely through web content without requiring user interaction beyond visiting a malicious website.
From an operational perspective, this vulnerability represents a critical security risk for any system running WebKitGTK versions before 2.36.8, including web browsers, embedded systems, and applications that rely on WebKitGTK for web content rendering. The remote code execution capability means that attackers can potentially compromise user systems simply by delivering malicious web content, making this a high-severity issue for web-based attack vectors. The vulnerability aligns with CWE-416, which specifically addresses use-after-free conditions, and can be mapped to attack techniques in the ATT&CK framework under T1203, which covers exploitation for execution through memory corruption vulnerabilities. Organizations using affected WebKitGTK versions face significant risk of unauthorized access, data theft, and system compromise.
The recommended mitigation strategy involves immediate upgrading to WebKitGTK version 2.36.8 or later where the vulnerability has been patched. Additionally, system administrators should implement network-level protections such as web application firewalls and content filtering to reduce exposure to malicious web content. Browser vendors and application developers should also consider implementing additional security mitigations including address space layout randomization, stack canaries, and other exploit prevention techniques. Regular security assessments and vulnerability scanning should be conducted to identify and remediate similar issues in other components of the web rendering stack. Organizations should also maintain updated threat intelligence feeds to monitor for exploit activity targeting this specific vulnerability.