CVE-2023-25363 in WebKitGTK
Summary
by MITRE • 03/02/2023
A use-after-free vulnerability in WebCore::RenderLayer::updateDescendantDependentFlags 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 resides within the WebKitGTK rendering engine's WebCore component, specifically in the WebCore::RenderLayer::updateDescendantDependentFlags method. The issue manifests as a use-after-free condition that occurs when the rendering layer system processes descendant elements and their dependent flags during the layout computation phase. This flaw represents a critical security risk that can be exploited by remote attackers to achieve arbitrary code execution on vulnerable systems. The vulnerability affects WebKitGTK versions prior to 2.36.8, making it a significant concern for applications and browsers that rely on this rendering engine for web content display.
The technical nature of this use-after-free vulnerability stems from improper memory management within the rendering layer's flag update mechanism. When the updateDescendantDependentFlags function processes descendant elements, it appears to free memory associated with certain layer objects while simultaneously maintaining references to those same objects in dependent flag computations. This creates a scenario where an attacker can manipulate the rendering process to cause the freed memory to be reallocated and subsequently accessed, leading to potential code execution. The vulnerability is particularly dangerous because it operates within the core rendering pipeline where web content is processed, making it accessible through standard web browsing activities.
The operational impact of this vulnerability extends beyond simple remote code execution to encompass a broad range of potential attacks. An attacker could craft malicious web content that, when rendered by a vulnerable WebKitGTK application, triggers the use-after-free condition. This could lead to complete system compromise, allowing attackers to install malware, steal sensitive data, or establish persistent access to affected systems. The vulnerability affects any application that utilizes WebKitGTK for web content rendering, including web browsers, email clients, and desktop applications with embedded web views. The remote exploitation capability means that victims need not interact with the malicious content directly, as the vulnerability can be triggered through standard web browsing operations.
Mitigation strategies for this vulnerability primarily focus on immediate version upgrades to WebKitGTK 2.36.8 or later, which contain the necessary patches to address the memory management issue. Organizations should prioritize patching affected systems and applications, particularly those that handle untrusted web content. Additionally, implementing network-level security controls such as web application firewalls and content filtering systems can provide additional protection layers. The vulnerability aligns with CWE-416, which specifically addresses use-after-free conditions, and represents a technique that could be mapped to ATT&CK tactic T1203, covering legitimate credentials and privilege escalation. Security monitoring should focus on detecting anomalous memory access patterns and unexpected code execution within rendering processes, as these behaviors may indicate exploitation attempts.