CVE-2015-9362 in Post Connector Plugin
Summary
by MITRE
The Post Connector plugin before 1.0.4 for WordPress has XSS via add_query_arg() and remove_query_arg().
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Analysis
by VulDB Data Team • 12/07/2023
The vulnerability identified as CVE-2015-9362 affects the Post Connector plugin for WordPress, specifically versions prior to 1.0.4, presenting a cross-site scripting vulnerability that could enable attackers to execute malicious scripts in the context of a victim's browser. This flaw resides within the plugin's handling of URL parameters through the add_query_arg() and remove_query_arg() functions, which are fundamental WordPress utility functions used for manipulating query strings in URLs. The vulnerability arises when user-supplied input is not properly sanitized or escaped before being processed by these functions, creating an avenue for malicious actors to inject harmful JavaScript code that can be executed when other users view affected pages.
The technical implementation of this vulnerability demonstrates a classic XSS flaw where the plugin fails to adequately validate and sanitize input parameters that are subsequently used to construct URLs. When the add_query_arg() and remove_query_arg() functions receive untrusted input without proper escaping mechanisms, they can inadvertently incorporate malicious script payloads into the generated URLs. This occurs because WordPress core functions do not automatically sanitize all user inputs when constructing query parameters, leaving developers to implement appropriate security measures. The vulnerability is particularly concerning as it leverages built-in WordPress functionality rather than requiring exploitation of more obscure or complex code paths, making it accessible to attackers with moderate technical skills.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform a range of malicious activities including session hijacking, credential theft, and data exfiltration. When authenticated users visit pages containing malicious query parameters, the injected scripts can access their browser sessions and potentially steal cookies or other sensitive information. The vulnerability also allows for more sophisticated attacks such as defacement of the WordPress site, redirection to malicious domains, or even privilege escalation if the affected user has administrative privileges. Since WordPress plugins often have broad access to site functionality and user data, the potential for damage increases significantly when attackers can leverage this vulnerability to compromise the entire WordPress installation.
Mitigation strategies for CVE-2015-9362 should focus on immediate patching of the affected plugin to version 1.0.4 or later, which contains the necessary security fixes. Organizations should also implement input validation and output escaping measures when using WordPress's add_query_arg() and remove_query_arg() functions, ensuring that all user-supplied parameters are properly sanitized before being incorporated into URLs. This aligns with CWE-79, which categorizes cross-site scripting vulnerabilities, and follows ATT&CK technique T1059.007 for script execution. Additionally, administrators should conduct thorough security audits of all installed plugins, implement proper content security policies, and maintain up-to-date security monitoring to detect potential exploitation attempts. Regular security assessments and vulnerability scanning should be performed to identify similar issues in other components of the WordPress ecosystem, as this vulnerability demonstrates the importance of proper input handling in web applications.