CVE-2006-3841 in WebScarab
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in WebScarab before 20060718-1904, when used with Microsoft Internet Explorer 6 SP2 or Konqueror 3.5.3, allows remote attackers to inject arbitrary web script or HTML via the URL, which is not sanitized before being returned in an error message when WebScarab is not able to access the URL.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 08/01/2018
The vulnerability identified as CVE-2006-3841 represents a critical cross-site scripting flaw in WebScarab, a web application security testing tool that was widely used for penetration testing and security auditing. This vulnerability specifically affects WebScarab versions prior to the 20060718-1904 release and demonstrates the inherent risks associated with improper input validation in security tools that process user-supplied data. The flaw becomes particularly dangerous when WebScarab is used in conjunction with Microsoft Internet Explorer 6 Service Pack 2 or Konqueror 3.5.3 web browsers, creating a perfect storm of exploitable conditions that could compromise user sessions and system integrity. The vulnerability stems from the application's failure to properly sanitize user input before incorporating it into error messages, which violates fundamental security principles and creates an attack surface that malicious actors can exploit.
The technical mechanism behind this vulnerability operates through a classic input sanitization failure where WebScarab accepts URLs from users without adequate validation or encoding of special characters. When the application attempts to access a malformed or malicious URL and fails to establish a connection, it generates an error message that includes the original URL without proper sanitization. This unfiltered output becomes embedded within the HTML response sent back to the user's browser, creating an XSS vector that can execute arbitrary script code in the context of the victim's session. The vulnerability specifically leverages the browser's handling of malformed URLs and the application's error reporting mechanism to deliver malicious payloads directly to users who are unaware of the underlying security risk. This flaw aligns with CWE-79, which defines cross-site scripting as a weakness where applications fail to properly validate or encode user-controllable data that is then embedded in generated HTML output.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable sophisticated attacks including session hijacking, credential theft, and data exfiltration. When security professionals use WebScarab for testing purposes, they become potential victims of their own tools, creating a dangerous paradox where the very software designed to identify security weaknesses becomes a vector for exploitation. Attackers can craft malicious URLs that, when processed by the vulnerable WebScarab version, would execute scripts in the context of other users' browsers who might be viewing the error messages. This creates a significant risk for organizations using WebScarab in production environments or for security teams that might inadvertently expose themselves to attacks through their own testing activities. The vulnerability also demonstrates how security tools themselves can become attack vectors, highlighting the need for comprehensive security testing of security tools as well as applications.
Mitigation strategies for this vulnerability require immediate patching of WebScarab to the affected version or newer releases that address the input sanitization issue. Organizations should implement strict input validation mechanisms that properly encode or escape special characters before including user data in error messages or any HTML output. The solution should incorporate proper HTML encoding techniques that convert potentially dangerous characters into their safe representations, preventing script execution in the browser context. Security teams should also consider implementing additional layers of protection including web application firewalls, content security policies, and regular security audits of all tools used in security testing environments. This vulnerability reinforces the ATT&CK framework's concept of privilege escalation through application vulnerabilities, where an attacker can exploit weaknesses in security tools to gain unauthorized access to systems or data. Regular updates and patch management processes become critical in preventing exploitation of such vulnerabilities, as the window of opportunity for attackers is often narrow but highly impactful when successfully exploited.