Source: cve@mitre.org
Cross-site scripting (XSS) vulnerability in the RSS Reader extension before 0.2.6 for MediaWiki allows remote attackers to inject arbitrary web script or HTML via a crafted feed.
MediaWiki's RSS Reader extension is vulnerable to a cross-site scripting (XSS) attack, allowing attackers to inject malicious HTML or JavaScript into the platform. This vulnerability can lead to account compromise, data theft, and website defacement by exploiting the way the extension processes RSS feeds. Successful exploitation requires a crafted RSS feed to be ingested by the vulnerable extension.
Step 1: Payload Creation: The attacker crafts a malicious RSS feed containing HTML or JavaScript code within the feed's title, description, or other relevant fields. This malicious code is designed to execute in the victim's browser.
Step 2: Feed Submission: The attacker either directly submits the malicious feed to the vulnerable RSS Reader extension or convinces a user to subscribe to it. This could involve social engineering or other techniques to trick users into adding the malicious feed.
Step 3: Feed Processing: The RSS Reader extension retrieves and parses the malicious feed. Due to the lack of proper sanitization, the injected HTML or JavaScript code remains intact.
Step 4: Content Rendering: When a user views the MediaWiki page that displays the feed content, the vulnerable extension renders the malicious HTML or executes the JavaScript code within the user's browser.
Step 5: Exploitation: The injected JavaScript code executes in the context of the user's session, allowing the attacker to perform actions such as stealing cookies, redirecting the user to a phishing site, or modifying the content of the MediaWiki page.
The vulnerability stems from insufficient input validation and output encoding within the RSS Reader extension. Specifically, the extension fails to properly sanitize or escape user-supplied data from RSS feed entries before rendering it on the MediaWiki page. This allows attackers to inject arbitrary HTML or JavaScript tags within the feed content. When a user views a page containing the malicious feed, the injected script executes in the context of the user's browser, enabling a range of attacks, including session hijacking, redirection to phishing sites, and the theft of sensitive information. The root cause is a lack of proper input validation and output encoding (e.g., HTML entity encoding) of the RSS feed data before it is displayed. The extension likely directly renders the feed content without sanitization, leading to the XSS vulnerability.
While no specific APTs are directly linked to this CVE, XSS vulnerabilities are commonly exploited by various threat actors. The impact of this vulnerability (account compromise, data theft) aligns with the goals of many malicious actors. CISA KEV status: Not Listed
Monitor web server logs for unusual HTTP requests, especially those containing JavaScript code or HTML tags in RSS feed parameters.
Inspect the RSS feed content for suspicious HTML or JavaScript code using content filtering tools or security scanners.
Analyze network traffic for unusual patterns, such as redirects to malicious domains or attempts to steal cookies.
Implement a Web Application Firewall (WAF) to detect and block XSS attempts.
Monitor user activity for suspicious behavior, such as unexpected changes to user accounts or page content.
Upgrade the RSS Reader extension to version 0.2.6 or later.
Implement a Web Application Firewall (WAF) to filter malicious input and prevent XSS attacks.
Apply input validation and output encoding to all user-supplied data, including RSS feed content. Specifically, escape HTML entities before rendering the feed content.
Regularly scan the MediaWiki installation for vulnerabilities using security scanners.
Educate users about the risks of clicking on suspicious links or subscribing to untrusted RSS feeds.
Implement a Content Security Policy (CSP) to restrict the execution of JavaScript code from untrusted sources.