CVE-2023-25360 in WebKitGTK
Summary
by MITRE • 03/02/2023
A use-after-free vulnerability in WebCore::RenderLayer::renderer 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 browser engine's rendering layer implementation, specifically in the WebCore::RenderLayer::renderer method where a use-after-free condition occurs. The flaw represents a critical memory safety issue that can be exploited to achieve remote code execution on affected systems. The vulnerability manifests when the rendering layer attempts to access memory that has already been freed, creating a scenario where maliciously crafted web content can manipulate the memory state to inject and execute arbitrary code. This type of vulnerability falls under the common weakness enumeration CWE-416, which catalogs use-after-free conditions as a fundamental memory safety flaw that has been consistently exploited in web browser vulnerabilities. The vulnerability affects WebKitGTK versions prior to 2.36.8, indicating that this issue has been present in the codebase for an extended period, allowing threat actors to develop and deploy exploitation techniques against unpatched systems. The attack vector requires remote code execution through web content delivery, making it particularly dangerous as it can be triggered simply by visiting a malicious website or receiving compromised web-based content. The operational impact extends beyond individual user compromise to potentially enable broader network infiltration, as successful exploitation could provide attackers with persistent access to target systems and facilitate lateral movement within networks.
The technical exploitation of this vulnerability involves manipulating the browser's rendering engine to trigger the use-after-free condition in the WebCore::RenderLayer::renderer component. When the rendering layer processes certain web content, it may create a scenario where a renderer object is freed from memory while references to it remain active in the rendering pipeline. Attackers can craft malicious web pages that force the browser into this specific memory state, where freed memory is subsequently accessed or overwritten with malicious data. The exploitation process typically leverages the predictable nature of memory layout in modern browsers to position malicious code within the freed memory space, effectively bypassing modern memory protection mechanisms such as stack canaries and address space layout randomization. This vulnerability directly aligns with the attack technique described in the MITRE ATT&CK framework under T1203, which covers exploitation for execution through memory corruption vulnerabilities. The attack chain can be initiated without user interaction in many cases, making it particularly insidious as it can be delivered through drive-by downloads or compromised websites that automatically exploit the vulnerability upon page load.
Mitigation strategies for this vulnerability require immediate patch deployment to upgrade WebKitGTK to version 2.36.8 or later, which contains the necessary memory management fixes to prevent the use-after-free condition. System administrators should prioritize patching across all affected platforms, particularly those running web browsers or web-based applications that utilize WebKitGTK components. Additional defensive measures include implementing browser hardening techniques such as disabling unnecessary JavaScript features, restricting access to potentially vulnerable web content, and deploying web application firewalls to filter malicious content. Organizations should also consider implementing network-based intrusion detection systems that can identify exploitation attempts targeting this specific vulnerability. The remediation process must account for the fact that this vulnerability affects a core rendering component that is integral to browser functionality, requiring careful testing of patches to ensure compatibility with existing web applications and services. Security monitoring should focus on detecting anomalous browser behavior patterns that might indicate exploitation attempts, including unusual memory access patterns or unexpected process behavior. The vulnerability's classification as a remote code execution flaw necessitates comprehensive network segmentation and access controls to limit the potential impact of successful exploitation attempts. Regular vulnerability assessments and penetration testing should be conducted to identify other potential memory safety issues within the browser ecosystem, as similar use-after-free conditions have been documented in other web browser components and can serve as indicators of broader security weaknesses in software architectures.