CVE-2012-3987 in Firefox
Summary
by MITRE
Mozilla Firefox before 16.0 on Android assigns chrome privileges to Reader Mode pages, which allows user-assisted remote attackers to bypass intended access restrictions via a crafted web site.
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Analysis
by VulDB Data Team • 04/18/2021
The vulnerability identified as CVE-2012-3987 represents a critical privilege escalation flaw in Mozilla Firefox versions prior to 16.0 on Android platforms. This issue stems from the improper handling of chrome privileges within Reader Mode functionality, which is designed to strip away distracting elements from web pages to provide a cleaner reading experience. The flaw allows malicious actors to exploit the privilege structure by crafting specially designed websites that can manipulate the browser's security model. This vulnerability specifically affects the Android version of Firefox, highlighting the platform-specific security considerations that must be addressed in mobile browser implementations.
The technical implementation of this vulnerability occurs through the Reader Mode feature's failure to properly isolate chrome privileges from regular web content. Chrome privileges typically refer to elevated permissions that allow access to browser internals and sensitive operations, which should remain restricted to trusted browser components. When Reader Mode pages receive these privileges, they can execute code with higher privileges than intended, creating a pathway for attackers to bypass the standard security boundaries that separate user content from browser infrastructure. This misconfiguration allows for the execution of malicious code that would normally be restricted, effectively undermining the browser's security model.
From an operational impact perspective, this vulnerability creates significant risks for Android users of Firefox, as it enables remote attackers to perform actions that should be impossible within the browser's security architecture. The user-assisted nature of the attack means that victims must visit a malicious website, but once triggered, the exploit can potentially lead to complete browser compromise, data theft, or further system exploitation. The vulnerability affects not just individual user privacy but also the integrity of the browser's security model, as it allows attackers to gain elevated privileges that could be used to access sensitive information or perform operations within the browser's restricted environment.
The security implications extend beyond simple privilege escalation, as this vulnerability aligns with several attack patterns documented in the ATT&CK framework, particularly those involving privilege escalation and exploitation of browser security mechanisms. This flaw demonstrates the importance of proper privilege separation in browser implementations and the risks associated with feature-specific security boundaries. Organizations and users should consider this vulnerability as part of broader mobile browser security assessments, as it highlights the need for comprehensive security testing of browser features that operate in restricted contexts. The vulnerability also underscores the importance of timely patch management, as the issue was resolved in Firefox version 16.0, emphasizing the critical nature of keeping browser software updated to address known security weaknesses.
This vulnerability type relates to CWE-276, which covers improper privilege management, and demonstrates how feature-specific security implementations can introduce unexpected access control vulnerabilities. The Android-specific nature of this flaw also highlights the importance of platform-specific security considerations in mobile browser development. Security professionals should monitor for similar privilege escalation patterns in other browser features and ensure proper isolation mechanisms are in place to prevent unauthorized access to privileged operations. The resolution of this vulnerability through the Firefox 16.0 update serves as a reminder of the critical importance of regular security updates in maintaining browser security posture and protecting users from known exploitation vectors.