CVE-2011-2999 in Firefox
Summary
by MITRE
Mozilla Firefox before 3.6.23 and 4.x through 5, Thunderbird before 6.0, and SeaMonkey before 2.3 do not properly handle "location" as the name of a frame, which allows remote attackers to bypass the Same Origin Policy via a crafted web site, a different vulnerability than CVE-2010-0170.
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Analysis
by VulDB Data Team • 11/20/2021
The vulnerability described in CVE-2011-2999 represents a critical security flaw in Mozilla Firefox, Thunderbird, and SeaMonkey web browsers that stems from improper handling of frame naming conventions. This issue specifically targets how browsers process the "location" property when used as a frame name, creating a pathway for malicious actors to circumvent fundamental web security mechanisms. The vulnerability affects versions prior to Firefox 3.6.23 and 4.x through 5, Thunderbird 6.0, and SeaMonkey 2.3, indicating a widespread impact across multiple browser implementations that were prevalent during this period. The flaw operates at the core of browser security architecture by exploiting the same origin policy enforcement mechanism that prevents unauthorized cross-site scripting attacks.
The technical implementation of this vulnerability involves the manipulation of frame objects within web documents where attackers can name a frame "location" and subsequently exploit this naming convention to access restricted properties and methods. This improper handling allows attackers to create malicious web pages that can bypass the same origin policy restrictions that normally prevent scripts from accessing data from different domains. The vulnerability differs from CVE-2010-0170, which indicates that this represents a distinct attack vector requiring specific frame naming patterns to achieve the bypass. When a frame is named "location", the browser's security model fails to properly enforce boundaries, enabling attackers to access sensitive information and execute unauthorized operations across domain boundaries. This flaw essentially creates a backdoor mechanism within the browser's frame handling system that undermines the fundamental security assumptions of web application isolation.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables sophisticated cross-site scripting attacks that could lead to complete session hijacking, data theft, and unauthorized access to user accounts. Attackers can leverage this vulnerability to construct malicious websites that appear legitimate to users while simultaneously gaining access to sensitive data from other domains, including cookies, session tokens, and personal information. The vulnerability is particularly dangerous because it operates silently in the background without user awareness, allowing attackers to harvest credentials and sensitive data without detection. This type of vulnerability directly violates the core principles of web security standards and represents a significant weakening of the browser's security model. The attack vector requires no special privileges from the user, as the exploitation occurs through normal web browsing activities, making it highly effective for mass deployment attacks.
Mitigation strategies for this vulnerability involve immediate patching of affected browser versions, as the primary fix requires updating to patched versions that properly handle frame naming conventions. Organizations should implement comprehensive browser update policies and ensure all users maintain current versions of their web browsers. Additionally, security teams should deploy network monitoring solutions to detect suspicious frame manipulation patterns and implement content security policies that restrict frame creation and access. The vulnerability aligns with ATT&CK technique T1059.007 for web application attacks and CWE-284 for improper access control, emphasizing the need for proper input validation and security boundary enforcement. Browser vendors should also consider implementing stricter frame naming validation and enhanced same origin policy enforcement mechanisms to prevent similar vulnerabilities from emerging in future implementations.