CVE-2011-5107 in Alert Before You Post
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in post_alert.php in Alert Before Your Post plugin, possibly 0.1.1 and earlier, for WordPress allows remote attackers to inject arbitrary web script or HTML via the name parameter.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 01/29/2025
The CVE-2011-5107 vulnerability represents a classic cross-site scripting flaw within the Alert Before Your Post WordPress plugin, specifically affecting versions 0.1.1 and earlier. This vulnerability resides in the post_alert.php script and demonstrates a critical weakness in input validation and output sanitization practices. The flaw allows remote attackers to inject malicious web scripts or HTML content through the name parameter, creating a persistent security risk that can be exploited across multiple user sessions.
The technical implementation of this vulnerability stems from inadequate sanitization of user-supplied input within the plugin's alert posting functionality. When users submit alert notifications through the WordPress interface, the name parameter is processed without proper validation or encoding, enabling attackers to inject malicious payloads that execute in the context of other users' browsers. This type of vulnerability falls under CWE-79, which specifically addresses Cross-Site Scripting flaws in software applications. The vulnerability exists because the plugin fails to implement proper input filtering mechanisms that would neutralize potentially dangerous characters and sequences before rendering user data in web responses.
The operational impact of CVE-2011-5107 extends beyond simple script injection, as it can enable attackers to perform various malicious activities including session hijacking, credential theft, and defacement of the affected WordPress site. An attacker could craft malicious payloads that redirect users to phishing sites, steal administrator cookies, or modify content displayed to other users. The vulnerability affects the entire WordPress ecosystem where the plugin is installed, potentially compromising multiple users and their associated data. According to ATT&CK framework, this vulnerability maps to T1566.001 (Phishing: Spearphishing Attachment) and T1059.007 (Command and Scripting Interpreter: JavaScript) techniques, as it enables attackers to execute JavaScript code in victims' browsers through crafted web content.
Mitigation strategies for CVE-2011-5107 require immediate action including upgrading to a patched version of the Alert Before Your Post plugin, which should implement proper input validation and output encoding. System administrators should also implement Content Security Policy headers to limit script execution capabilities, employ web application firewalls to detect and block malicious payloads, and conduct regular security audits of installed plugins. Additionally, the vulnerability highlights the importance of input validation at multiple layers within web applications, as recommended by OWASP Top Ten security practices. Organizations should also consider implementing principle of least privilege access controls and regular security monitoring to detect potential exploitation attempts. The remediation process must include thorough testing of updated plugins to ensure compatibility while addressing the XSS vulnerability through proper sanitization techniques such as HTML entity encoding and strict input filtering mechanisms.