CVE-2007-0896 in Sage
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the (1) Sage before 1.3.10, and (2) Sage++ extensions for Firefox, allows remote attackers to inject arbitrary web script or HTML via a "<SCRIPT/= SRC= " sequence in an RSS feed, a different vulnerability than CVE-2006-4712.
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Analysis
by VulDB Data Team • 02/19/2025
The vulnerability described in CVE-2007-0896 represents a critical cross-site scripting flaw affecting the Sage and Sage++ browser extensions for Firefox. This vulnerability specifically targets versions prior to 1.3.10 of the Sage extension and demonstrates how web browser add-ons can become attack vectors for executing malicious code against unsuspecting users. The flaw resides in the improper handling of RSS feed content within these extensions, creating a pathway for remote attackers to inject arbitrary web scripts or HTML code into user sessions.
The technical implementation of this vulnerability involves a specific payload pattern using the "<SCRIPT/= SRC=" sequence within RSS feed data. This particular construction exploits parsing inconsistencies in how the Sage extensions process incoming feed content, allowing attackers to bypass normal input validation mechanisms. The vulnerability operates at the application layer and requires no privileged access to execute successfully, making it particularly dangerous in environments where users frequently consume RSS feeds through these extensions. The flaw specifically affects the extension's RSS feed parser, which fails to properly sanitize or escape special characters in feed content before rendering it in the browser context.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to perform session hijacking, steal cookies, redirect users to malicious websites, or execute arbitrary commands on behalf of the victim. Users who regularly access RSS feeds through the affected Sage extensions become potential victims, with their browser sessions compromised when they encounter maliciously crafted feed content. The vulnerability creates a persistent threat vector since RSS feeds are commonly used for news aggregation, blog updates, and other legitimate content distribution methods, making it difficult for users to distinguish between benign and malicious content.
This vulnerability aligns with CWE-79, which defines Cross-Site Scripting as a weakness where untrusted data is sent to a web browser without proper validation or escaping, allowing attackers to inject client-side scripts. From an ATT&CK framework perspective, this vulnerability maps to T1059.007 for Command and Scripting Interpreter: JavaScript and T1566 for Phishing, as attackers can leverage this flaw to deliver malicious JavaScript payloads through seemingly legitimate RSS feeds. The attack chain typically begins with an attacker crafting a malicious RSS feed containing the "<SCRIPT/= SRC=" payload, which when consumed by an affected Sage extension, executes the injected code in the user's browser context. Organizations should consider this vulnerability as part of their broader web application security posture, particularly when evaluating browser extension security and input validation practices. Mitigation strategies include immediate patching of affected Sage extensions to version 1.3.10 or later, implementing strict content filtering policies for RSS feeds, and educating users about the risks of consuming untrusted feed content.