CVE-2009-4524

Source: cve@mitre.org

MEDIUM
4.3
Published: December 31, 2009 at 07:30 PM
Modified: April 9, 2025 at 12:30 AM

Vulnerability Description

Cross-site scripting (XSS) vulnerability in the RealName module 6.x-1.x before 6.x-1.3 for Drupal allows remote attackers to inject arbitrary web script or HTML via a realname (aka real name) element.

CVSS Metrics

Base Score
4.3
Severity
MEDIUM
Vector String
AV:N/AC:M/Au:N/C:N/I:P/A:N

Weaknesses (CWE)

Source: nvd@nist.gov

AI Security Analysis

01 // Technical Summary

Drupal websites using the RealName module are vulnerable to Cross-Site Scripting (XSS) attacks, allowing attackers to inject malicious scripts into web pages viewed by other users. This can lead to session hijacking, defacement, or the theft of sensitive information. Successful exploitation requires a user to interact with a crafted link or content, making it a medium-severity vulnerability.

02 // Vulnerability Mechanism

Step 1: Payload Delivery: An attacker crafts a malicious payload, typically JavaScript, and embeds it within the 'realname' field when creating or updating a user profile.

Step 2: Data Storage: The attacker's malicious payload is stored in the Drupal database associated with the user's realname.

Step 3: User Interaction: A legitimate user visits a page where the attacker's 'realname' is displayed. This could be a user profile page, a comment section, or any other area where the realname is rendered.

Step 4: Payload Execution: The vulnerable RealName module retrieves the attacker's realname from the database and renders it on the page without proper sanitization. The browser then executes the embedded JavaScript payload.

Step 5: Attack Execution: The executed JavaScript performs the attacker's desired actions, such as stealing cookies, redirecting the user to a phishing site, or defacing the website.

03 // Deep Technical Analysis

The vulnerability stems from insufficient input validation and output encoding within the RealName module. Specifically, the module fails to properly sanitize user-supplied input for the 'realname' field before rendering it on a webpage. This allows attackers to inject arbitrary HTML or JavaScript code. The root cause is a lack of HTML entity encoding or input sanitization on the user-provided realname data before it's displayed. The module likely directly outputs the user-provided name without proper escaping, leading to the XSS vulnerability.

04 // Exploitation Status

Public PoC is available. While the vulnerability is old, XSS vulnerabilities are often easy to exploit, and the widespread use of Drupal makes this a potentially attractive target. The vulnerability is likely not **Actively exploited** by sophisticated actors, but it is a low-hanging fruit for opportunistic attackers.

05 // Threat Intelligence

While no specific APTs are directly linked to this specific CVE, XSS vulnerabilities are commonly used by various threat actors. This vulnerability could be exploited by script kiddies or used as part of a larger attack chain. CISA KEV status: Not Listed

06 // Detection & Hunting

  • Review web server logs for suspicious HTTP requests containing JavaScript payloads in the 'realname' field or similar user-input fields.

  • Monitor network traffic for unusual JavaScript execution or redirects originating from the Drupal website.

  • Implement a Web Application Firewall (WAF) with XSS detection rules.

  • Use a Content Security Policy (CSP) to restrict the execution of JavaScript from untrusted sources.

07 // Remediation & Hardening

  • Upgrade the RealName module to version 6.x-1.3 or later.

  • Implement input validation to sanitize user-supplied data, ensuring that potentially malicious characters (e.g., < , > , &) are properly encoded.

  • Implement output encoding (HTML entity encoding) to escape user-supplied data before rendering it in HTML.

  • Use a WAF to filter malicious requests.

  • Regularly update the Drupal core and all installed modules to the latest security patches.

  • Implement a Content Security Policy (CSP) to mitigate XSS attacks.

08 // Affected Products

Drupal with the RealName module installed.RealName module versions 6.x-1.x before 6.x-1.3

09 // Discovered Proof of Concept Links

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