CVE-2008-0940 in WebGUI
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Plain Black WebGUI before 7.4.24 allows remote attackers to inject arbitrary web script or HTML when creating a username, a different vulnerability than CVE-2007-0407.
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Analysis
by VulDB Data Team • 09/16/2018
The cross-site scripting vulnerability identified as CVE-2008-0940 affects Plain Black WebGUI versions prior to 7.4.24 and represents a critical security flaw that enables remote attackers to execute malicious scripts within the context of affected user sessions. This vulnerability specifically manifests when users create usernames within the web application, creating a persistent vector for attackers to inject arbitrary web script or HTML content that can be executed by other users who view the affected username.
The technical implementation of this XSS vulnerability stems from inadequate input validation and output encoding mechanisms within the WebGUI application's username creation functionality. When users submit usernames containing malicious script code, the application fails to properly sanitize or escape the input before rendering it in web pages, allowing attackers to inject JavaScript code or HTML elements that execute in the browsers of other users. This type of vulnerability falls under CWE-79 which specifically addresses cross-site scripting flaws where untrusted data is improperly incorporated into web pages without proper validation or encoding.
The operational impact of this vulnerability extends beyond simple script execution as it provides attackers with a foothold for more sophisticated attacks including session hijacking, credential theft, and data exfiltration. Attackers can craft malicious usernames that, when viewed by other users, execute scripts that steal session cookies, redirect users to malicious sites, or perform unauthorized actions on behalf of the victim. The vulnerability's persistence in the username creation process means that the malicious content remains embedded in the application until the username is modified or the vulnerability is patched, creating a long-term threat vector.
This vulnerability differs from CVE-2007-0407, indicating that while both affect the same application, they target different code paths or input validation points within the system. The distinction is important for security teams as it suggests multiple attack surfaces within the same application that require comprehensive patching and validation strategies. From an attacker's perspective, this vulnerability aligns with ATT&CK technique T1059.007 which covers scripting through web shells and malicious code injection, providing a pathway for attackers to establish persistent access or escalate privileges within the application environment.
The recommended mitigation strategy involves upgrading to Plain Black WebGUI version 7.4.24 or later, which contains the necessary patches to address the input validation and output encoding deficiencies. Organizations should also implement additional defensive measures including input sanitization, output encoding, and Content Security Policy (CSP) headers to provide layered protection against similar vulnerabilities. Security teams should conduct thorough penetration testing and code reviews to identify potential similar vulnerabilities in other application components and ensure that all user-supplied input undergoes proper validation and sanitization before being rendered in web contexts.