CVE-2009-4677 in phpFK PHP Forum
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in search.php in phpFK PHP Forum ohne 7.0.4 allows remote attackers to inject arbitrary web script or HTML via the search parameter. NOTE: the provenance of this information is unknown; the details are obtained solely from third party information.
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Analysis
by VulDB Data Team • 05/02/2026
The vulnerability identified as CVE-2009-4677 represents a classic cross-site scripting flaw within the phpFK PHP Forum software version 7.0.4. This security weakness specifically affects the search.php script, which serves as a critical component for user interaction and content retrieval within the forum environment. The vulnerability stems from inadequate input validation and sanitization mechanisms that fail to properly process user-supplied data before incorporating it into web responses. The search parameter functionality becomes a vector for malicious code injection, allowing unauthorized actors to execute arbitrary web scripts or HTML content within the context of other users' browsers.
The technical implementation of this vulnerability aligns with CWE-79, which categorizes cross-site scripting as a code injection flaw where untrusted data is improperly integrated into web pages without adequate sanitization. The flaw occurs when the application directly incorporates user input from the search parameter into dynamic web content without proper encoding or validation. This creates an environment where attackers can craft malicious payloads that persist in the forum's search functionality and execute automatically when other users access search results or related pages. The vulnerability's impact extends beyond simple script execution to potentially enable session hijacking, credential theft, and other sophisticated attacks that leverage the trust relationship between the victim's browser and the vulnerable forum application.
From an operational perspective, this XSS vulnerability presents significant risks to forum users and administrators alike. Attackers can exploit the flaw to inject malicious JavaScript code that could redirect users to phishing sites, steal session cookies, or modify forum content in ways that compromise user experience and data integrity. The attack surface is particularly concerning given that forum software typically handles sensitive user information including personal messages, profile data, and potentially confidential communications. The vulnerability's remote exploitability means that attackers do not require local system access or authentication to carry out malicious activities, making it particularly dangerous for publicly accessible forum installations. The impact is amplified by the fact that forum users often trust the platform and may not suspect malicious content in search results or discussion threads.
Security mitigations for this vulnerability should focus on implementing comprehensive input validation and output encoding mechanisms. The primary defense involves sanitizing all user input through proper escaping techniques before incorporating it into web responses, specifically applying HTML entity encoding to prevent script execution. Implementing a Content Security Policy (CSP) header can provide additional protection by restricting the sources from which scripts can be loaded and executed within the forum environment. Regular security audits and code reviews should be conducted to identify similar input handling vulnerabilities throughout the application. The vulnerability also underscores the importance of keeping forum software updated with the latest security patches, as this flaw represents a known issue that was likely addressed in subsequent releases. Organizations should also implement web application firewalls to detect and block suspicious input patterns, and establish proper security monitoring to identify potential exploitation attempts. The remediation process should include thorough testing to ensure that input sanitization does not break legitimate functionality while effectively neutralizing the XSS attack vector.