CVE-2009-4888 in PHortail
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in poster.php in PHortail 1.2.1 allows remote attackers to inject arbitrary web script or HTML via the (1) pseudo, (2) email, (3) ti, and (4) txt parameters.
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Analysis
by VulDB Data Team • 07/29/2025
The CVE-2009-4888 vulnerability represents a critical cross-site scripting flaw in the PHortail 1.2.1 web application that exposes users to potential malicious code execution. This vulnerability resides within the poster.php script which serves as a forum posting interface, making it a prime target for attackers seeking to compromise user sessions and inject malicious content into the application's user interface. The flaw specifically affects four input parameters including pseudo for username, email for contact information, ti for topic title, and txt for message content, all of which are processed without proper sanitization or validation. The vulnerability classification aligns with CWE-79 which defines cross-site scripting as a weakness where untrusted data is sent to a web browser without proper validation or encoding, allowing attackers to inject malicious scripts that execute in the context of other users' browsers.
The technical exploitation of this vulnerability occurs when remote attackers submit malicious input through any of the four vulnerable parameters, allowing them to inject arbitrary HTML or JavaScript code that gets executed when other users view the affected forum posts. This creates a persistent XSS attack vector where malicious scripts can steal session cookies, redirect users to malicious sites, or perform actions on behalf of authenticated users. The attack requires no special privileges and can be executed through simple HTTP requests, making it particularly dangerous as it can affect any user who views the compromised content. The vulnerability's impact is amplified because forum applications typically serve as trusted environments where users expect safe interaction with content, making the injection of malicious scripts particularly effective for social engineering attacks.
From an operational perspective, this vulnerability creates significant risks for organizations using PHortail 1.2.1 as it enables attackers to compromise user accounts, steal sensitive information, and potentially escalate privileges within the application. The attack surface extends beyond simple script injection to include session hijacking, data exfiltration, and the potential for establishing persistent backdoors through more sophisticated attack vectors. Users who access the forum regularly become targets for these attacks, with the malicious scripts executing automatically when they view affected posts. The vulnerability also poses risks to the application's integrity and the trust users place in the platform, potentially leading to reputation damage and loss of user confidence in the system's security measures.
Security mitigations for this vulnerability should focus on implementing proper input validation and output encoding mechanisms throughout the application. The most effective immediate solution involves sanitizing all user-supplied input through strict validation processes that reject or encode potentially dangerous characters before processing or storing the data. The application should implement context-appropriate output encoding for all parameters displayed in the user interface, ensuring that any potentially malicious content is rendered harmless. Additionally, implementing a content security policy can provide an additional layer of protection by restricting script execution and preventing unauthorized code injection. Organizations should also consider implementing proper access controls and monitoring for suspicious activity patterns that might indicate exploitation attempts. This vulnerability demonstrates the critical importance of input validation and output encoding practices as outlined in the OWASP Top Ten security risks and aligns with ATT&CK technique T1059.002 for command and scripting interpreter execution through web-based attacks. Regular security updates and vulnerability assessments should be conducted to identify similar issues in legacy applications and ensure proper security controls are in place to prevent such persistent threats from compromising user data and system integrity.