CVE-2009-4101 in infoRSS
Summary
by MITRE
infoRSS 1.1.4.2 and earlier extension for Firefox performs certain operations with chrome privileges, which allows remote attackers to execute arbitrary commands and perform cross-domain scripting attacks via the description tag of an RSS feed.
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Analysis
by VulDB Data Team • 01/23/2019
The vulnerability identified as CVE-2009-4101 affects the infoRSS extension version 1.1.4.2 and earlier for the Mozilla Firefox web browser. This security flaw represents a critical privilege escalation issue that exploits the extension's improper handling of chrome privileges within the browser's security model. The vulnerability stems from the extension's failure to properly validate and sanitize input data from RSS feed descriptions, creating a dangerous attack vector that bypasses standard browser security boundaries.
The technical implementation of this vulnerability involves the infoRSS extension operating with elevated chrome privileges that should normally be restricted to the browser's core components. When processing RSS feed data, particularly the description tag, the extension fails to properly sanitize user-supplied content, allowing malicious actors to inject executable code that leverages these elevated privileges. This flaw enables remote attackers to execute arbitrary commands on the victim's system with the same privileges as the browser itself, effectively compromising the entire user environment. The cross-domain scripting capability further amplifies the impact by allowing attackers to bypass standard web security restrictions and access resources across different domains.
From an operational perspective, this vulnerability creates a severe threat landscape for users who rely on RSS feeds for information consumption. Attackers can craft malicious RSS feeds that, when processed by the vulnerable extension, trigger remote code execution on the victim's machine. The impact extends beyond simple command execution to include potential data theft, system compromise, and lateral movement within the network. The vulnerability's remote exploitation capability means that users can be compromised simply by viewing an infected RSS feed in their browser, making it particularly dangerous in environments where users frequently consume third-party content. This type of vulnerability directly maps to CWE-94, which describes "Improper Control of Generation of Code" and aligns with ATT&CK technique T1059.007 for "Command and Scripting Interpreter: JavaScript" and T1068 for "Exploitation for Privilege Escalation."
The mitigation strategies for this vulnerability require immediate action from affected users, including upgrading to the patched version of the infoRSS extension or disabling the extension entirely. Organizations should implement network monitoring to detect potential exploitation attempts and ensure that browser extensions are regularly updated and vetted for security. Security administrators should consider implementing browser security policies that restrict extension privileges and regularly audit installed browser extensions for known vulnerabilities. The vulnerability also highlights the importance of proper input validation and privilege separation in browser extension development, emphasizing the need for extensions to operate with minimal required privileges and to properly sanitize all user-supplied input. Additionally, users should be educated about the risks of consuming untrusted RSS feeds and the importance of keeping browser extensions updated to prevent exploitation of such critical vulnerabilities.