CVE-2009-2571 in VerliAdmin
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in index.php in VerliAdmin 0.3.7 and 0.3.8 allow remote attackers to inject arbitrary web script or HTML via (1) the URI, (2) the q parameter, (3) the nick parameter, or (4) the nick parameter in a bantest action.
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Analysis
by VulDB Data Team • 09/14/2025
The vulnerability described in CVE-2009-2571 represents a critical cross-site scripting flaw affecting VerliAdmin versions 0.3.7 and 0.3.8. This vulnerability falls under the CWE-79 category of Cross-Site Scripting, which is one of the most prevalent and dangerous web application security weaknesses identified by the Common Weakness Enumeration standard. The flaw manifests in the index.php file where user input parameters are not properly sanitized or validated before being rendered back to users in web responses, creating an exploitable condition that enables malicious actors to inject arbitrary script code into web pages viewed by other users.
The technical implementation of this vulnerability occurs through four specific attack vectors that all originate from unsanitized user input. The first vector involves URI manipulation where attackers can inject malicious scripts through the URL structure itself. The second vector targets the q parameter, which is commonly used for search queries or general application parameters in web applications. The third and fourth vectors focus on the nick parameter, with the fourth specifically mentioning the nick parameter during a bantest action, indicating that the vulnerability exists not only in general parameter handling but also in specialized administrative functions. These multiple attack surfaces significantly increase the exploitability of the vulnerability.
The operational impact of this vulnerability is severe as it allows remote attackers to execute malicious scripts in the context of affected users' browsers, potentially leading to session hijacking, credential theft, or unauthorized administrative actions. The XSS attack can be executed without requiring any special privileges or authentication, making it particularly dangerous for web applications that handle sensitive data or administrative functions. When users visit a maliciously crafted URL or interact with content containing the injected script, their browsers will execute the malicious code, potentially compromising their sessions and allowing attackers to perform actions as if they were the legitimate users.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and output encoding techniques to prevent malicious scripts from being executed. The recommended approach includes implementing strict input sanitization for all user-supplied parameters, particularly those used in URI construction, query parameters, and form fields. Web application developers should employ context-specific output encoding to ensure that any user-controllable data is properly escaped when rendered in HTML contexts. Additionally, implementing a Content Security Policy (CSP) header can provide an additional layer of protection by restricting the sources from which scripts can be loaded and executed. Organizations should also consider implementing proper parameter validation and sanitization at multiple layers of their web application architecture to prevent similar vulnerabilities from occurring in other components. The vulnerability demonstrates the importance of following secure coding practices and adhering to the principle of least privilege in web application development, ensuring that user input is never directly trusted or rendered without proper sanitization. This vulnerability aligns with ATT&CK technique T1566.001 for Phishing and T1059.001 for Command and Scripting Interpreter, as it enables attackers to establish persistent access through malicious script injection and execute arbitrary commands in user browsers.