CVE-2016-9896 in Firefox
Summary
by MITRE
Use-after-free while manipulating the "navigator" object within WebVR. Note: WebVR is not currently enabled by default. This vulnerability affects Firefox < 50.1.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 10/08/2022
The vulnerability identified as CVE-2016-9896 represents a critical use-after-free condition that occurs during manipulation of the navigator object within the WebVR implementation in Firefox browsers. This flaw exists in the browser's handling of virtual reality web APIs and specifically affects versions prior to Firefox 50.1. The issue stems from improper memory management when the browser processes WebVR-related JavaScript code that interacts with the navigator object, which serves as a fundamental interface for web applications to access browser and device information.
The technical execution of this vulnerability involves a scenario where a malicious web page could trigger a use-after-free condition by manipulating the navigator object in conjunction with WebVR functionality. When the browser processes certain JavaScript code that attempts to access or modify the navigator object while WebVR is involved, the memory previously allocated to that object may be freed but still referenced by subsequent operations. This creates a situation where attackers can potentially execute arbitrary code or cause browser crashes through carefully crafted web content that exploits the improper memory handling within the WebVR implementation.
The operational impact of this vulnerability is significant as it allows remote code execution capabilities when exploited, potentially enabling attackers to take control of affected systems. The vulnerability affects Firefox versions before 50.1, making it particularly dangerous for users who have not updated their browsers to the patched versions. Since WebVR was not enabled by default, exploitation would require specific conditions where the feature was activated or where the attacker could force its activation through social engineering or other means. This use-after-free condition could lead to complete system compromise, data theft, or further malware deployment.
The vulnerability aligns with CWE-416, which specifically addresses use-after-free conditions in software implementations, and can be mapped to ATT&CK technique T1059.007 for script-based attacks that leverage browser vulnerabilities. Organizations should prioritize updating Firefox installations to version 50.1 or later to mitigate this risk, while security teams should monitor for any exploitation attempts targeting this specific memory management flaw. Additional mitigations include disabling WebVR functionality in browser settings when not required, implementing network-based protections such as web application firewalls, and conducting regular security assessments to identify potential exploitation vectors. The vulnerability demonstrates the importance of proper memory management in browser implementations and highlights the risks associated with complex web APIs that interact with system resources.