CVE-2011-3384 in Sage
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the Sage add-on 1.3.10 and earlier for Firefox allows remote attackers to inject arbitrary web script or HTML via a crafted feed, a different vulnerability than CVE-2009-4102.
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Analysis
by VulDB Data Team • 02/10/2019
The CVE-2011-3384 vulnerability represents a cross-site scripting flaw in the Sage Firefox add-on version 1.3.10 and earlier, exposing users to potential remote code execution through malicious web content injection. This vulnerability specifically affects the handling of crafted RSS or Atom feeds within the browser extension environment, creating a persistent security risk for users who rely on the add-on for content aggregation and management. The flaw stems from insufficient input validation and output sanitization mechanisms within the Sage extension's feed processing pipeline, allowing attackers to inject malicious scripts that execute in the context of the user's browser session.
The technical implementation of this vulnerability involves the Sage add-on's failure to properly sanitize user-supplied feed data before rendering it within the browser interface. When users subscribe to malicious feeds, the extension processes the content without adequate protection against script injection attacks, creating a pathway for attackers to execute arbitrary JavaScript code within the user's browsing context. This behavior aligns with CWE-79, which categorizes cross-site scripting vulnerabilities as weaknesses in input validation and output encoding, specifically targeting the failure to properly escape or filter user-controllable data before it is rendered in web pages. The vulnerability operates at the application layer, exploiting the trust relationship between the browser extension and its users, and can be leveraged to perform actions such as cookie theft, session hijacking, or redirection to malicious websites.
The operational impact of CVE-2011-3384 extends beyond simple script injection, as it provides attackers with a persistent foothold within the user's browser environment. Once exploited, the vulnerability enables threat actors to access sensitive information stored within the browser, manipulate user interactions with websites, and potentially escalate privileges through more sophisticated attack vectors. The risk is particularly elevated for users who regularly access RSS feeds from untrusted sources, as the vulnerability can be triggered through legitimate subscription mechanisms without requiring user interaction beyond normal browsing activities. This attack surface aligns with ATT&CK technique T1059.007, which describes the use of scripting languages for execution, and represents a common vector for delivering malicious payloads in web-based attack campaigns. The vulnerability's persistence across multiple feed types and its ability to operate without user awareness makes it particularly dangerous in enterprise environments where users may unknowingly subscribe to compromised feeds.
Mitigation strategies for CVE-2011-3384 should prioritize immediate patching of the Sage add-on to version 1.3.11 or later, which contains the necessary input validation and sanitization fixes. Organizations should implement feed validation policies that restrict subscriptions to trusted sources and employ content filtering mechanisms to detect and block suspicious feed content before it reaches end users. Network-level protections such as web application firewalls and security scanning tools can help identify and prevent exploitation attempts. Additionally, user education programs should emphasize the risks of subscribing to untrusted feeds and the importance of verifying feed sources before adding them to browser extensions. The vulnerability demonstrates the importance of secure coding practices in browser extensions, particularly regarding input validation and output encoding, and serves as a reminder of the critical security considerations when developing add-ons that process external content. Regular security audits and penetration testing of browser extensions can help identify similar vulnerabilities before they can be exploited by threat actors, while adherence to security standards such as those defined in the OWASP Top Ten provides a framework for preventing such issues in future development cycles.