CVE-2006-4881 in PHP-Post
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in David Bennett PHP-Post (PHPp) 1.0 and earlier allow remote attackers to inject arbitrary web script or HTML via (1) the replyuser parameter in (a) pm.php; (2) the txt_jumpto parameter in (b) dropdown.php; the (3) txt_error and (4) txt_templatenotexist parameters in (c) template.php; the (5) split parameter in certain files, as demonstrated by (d) editprofile.php, (e) search.php, (f) index.php, and (g) pm.php; and the (6) txt_login parameter in (h) loginline.php; and allow remote authenticated users to inject arbitrary web script or HTML via the (7) txt_logout parameter in (i) loginline.php.
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Analysis
by VulDB Data Team • 08/04/2018
The CVE-2006-4881 vulnerability represents a critical cross-site scripting flaw in PHP-Post (PHPp) version 1.0 and earlier, affecting multiple components within the application's codebase. This vulnerability stems from inadequate input validation and sanitization mechanisms that fail to properly escape or filter user-supplied data before rendering it in web responses. The flaw manifests across several PHP files including pm.php, dropdown.php, template.php, editprofile.php, search.php, index.php, and loginline.php, demonstrating a widespread issue in the application's security architecture.
The technical implementation of this vulnerability occurs when user input parameters are directly incorporated into HTML output without proper sanitization. Specifically, the replyuser parameter in pm.php, txt_jumpto parameter in dropdown.php, and txt_error and txt_templatenotexist parameters in template.php all accept unfiltered input that can be exploited to inject malicious scripts. Additionally, the split parameter across multiple files including editprofile.php, search.php, index.php, and pm.php creates further attack vectors where user-supplied data can be manipulated to execute arbitrary code in the context of other users' browsers.
The operational impact of this vulnerability is severe as it allows remote attackers to execute malicious scripts in the browsers of unsuspecting users who visit affected pages. This creates a persistent threat where attackers can steal session cookies, perform unauthorized actions on behalf of users, redirect them to malicious sites, or deface the application's content. The vulnerability affects both unauthenticated and authenticated users, with the latter category being particularly concerning as it allows attackers to exploit the txt_logout parameter in loginline.php to inject scripts even when users are logged in, potentially compromising their sessions and access privileges.
From a cybersecurity framework perspective, this vulnerability aligns with CWE-79 (Cross-site Scripting) and maps to ATT&CK technique T1059.001 (Command and Scripting Interpreter: PowerShell) and T1566 (Phishing) as attackers can leverage these XSS flaws to deliver malicious payloads. The vulnerability demonstrates poor input validation practices that violate security best practices outlined in OWASP Top Ten and NIST Cybersecurity Framework. The attack surface is extensive given that multiple files across the application are affected, and the exploitation requires minimal privileges since the vulnerability can be triggered by remote attackers without authentication.
Organizations should implement comprehensive mitigations including input validation, output encoding, and proper sanitization of all user-supplied data before rendering it in web responses. The recommended approach involves implementing Content Security Policy headers, using proper HTML escaping functions, and ensuring all parameters are validated against expected input patterns. Additionally, regular security audits and code reviews should be conducted to identify similar vulnerabilities in legacy applications, while upgrading to supported versions of PHP-Post or migrating to more secure alternatives represents the most effective long-term solution. The vulnerability highlights the critical importance of secure coding practices and proper input sanitization in preventing widespread XSS attacks that can compromise entire web applications and their user bases.