CVE-2012-1944 in Firefox
Summary
by MITRE
The Content Security Policy (CSP) implementation in Mozilla Firefox 4.x through 12.0, Firefox ESR 10.x before 10.0.5, Thunderbird 5.0 through 12.0, Thunderbird ESR 10.x before 10.0.5, and SeaMonkey before 2.10 does not block inline event handlers, which makes it easier for remote attackers to conduct cross-site scripting (XSS) attacks via a crafted HTML document.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 10/21/2024
The vulnerability described in CVE-2012-1944 represents a critical flaw in the Content Security Policy implementation within several Mozilla browser products including Firefox and Thunderbird. This weakness specifically targets the enforcement of CSP directives that should prevent inline script execution and event handlers. The vulnerability affects versions ranging from Firefox 4.x through 12.0, Firefox ESR 10.x before 10.0.5, Thunderbird 5.0 through 12.0, Thunderbird ESR 10.x before 10.0.5, and SeaMonkey before 2.10, creating a significant attack surface that could be exploited by malicious actors.
The technical flaw lies in the incomplete implementation of CSP that fails to properly block inline event handlers such as onclick, onload, and other JavaScript event attributes embedded directly within HTML elements. This occurs because the Content Security Policy specification includes directives like script-src and object-src that should prevent execution of inline scripts and event handlers, but the affected Mozilla products did not properly enforce these restrictions. The vulnerability stems from the browser's failure to distinguish between inline event handlers and external script references, allowing attackers to bypass security controls that were intended to prevent cross-site scripting attacks.
The operational impact of this vulnerability is severe as it enables remote attackers to conduct sophisticated cross-site scripting attacks without requiring additional exploitation techniques. Attackers can craft malicious HTML documents containing inline event handlers that execute malicious JavaScript code when users view the content in affected browsers. This creates a direct pathway for session hijacking, data theft, and other malicious activities since the CSP mechanism that should provide protection against such attacks is effectively circumvented. The vulnerability particularly affects web applications that rely on CSP for XSS protection, as it allows attackers to bypass these security controls entirely.
This vulnerability aligns with CWE-16, which describes issues in the design or implementation of security features, specifically focusing on the improper implementation of security controls. From an ATT&CK framework perspective, this vulnerability maps to T1211, which covers the use of external remote services for command and control, and T1566, which involves the delivery of malicious payloads through phishing or compromised websites. The exploitation of this vulnerability demonstrates the importance of proper CSP implementation and enforcement in preventing client-side attacks that could compromise user sessions and data integrity.
The recommended mitigations for this vulnerability include immediate patching of affected browser versions to the latest releases that contain proper CSP implementation. Organizations should also implement additional security measures such as strict CSP headers that include 'unsafe-inline' restrictions and regular security audits of web applications to ensure proper CSP enforcement. Browser vendors should maintain rigorous testing procedures for security features and ensure comprehensive implementation of web standards including CSP to prevent similar issues in future releases. Users should be educated about the risks of visiting untrusted websites and the importance of keeping browser software updated to protect against known vulnerabilities.