CVE-2015-7377 in Pie Register Plugin
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in pie-register/pie-register.php in the Pie Register plugin before 2.0.19 for WordPress allows remote attackers to inject arbitrary web script or HTML via the invitaion_code parameter in a pie-register page to the default URI.
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Analysis
by VulDB Data Team • 06/22/2022
The CVE-2015-7377 vulnerability represents a critical cross-site scripting flaw in the Pie Register WordPress plugin, which affected versions prior to 2.0.19. This vulnerability resides within the plugin's handling of user input through the invitation_code parameter, creating a persistent security risk for WordPress installations that utilize this registration plugin. The flaw specifically manifests when the plugin processes the invitation_code parameter in pie-register pages, allowing malicious actors to inject arbitrary web scripts or HTML content into the application's response. This type of vulnerability falls under CWE-79, which categorizes cross-site scripting as a critical weakness in web applications where user-provided data is not properly sanitized before being rendered in web pages.
The technical exploitation of this vulnerability occurs through a straightforward injection mechanism where remote attackers can manipulate the invitation_code parameter to inject malicious code that executes in the context of other users' browsers. When the plugin fails to properly validate or escape the invitation_code input, the injected scripts can execute with the privileges of the victim user, potentially leading to session hijacking, credential theft, or other malicious activities. The vulnerability's impact is amplified because it affects the default URI of the plugin, meaning that any user visiting a page that processes this parameter could be exposed to the malicious payload without requiring special conditions or user interaction beyond navigating to the affected page.
The operational impact of this vulnerability extends beyond simple script injection, as it creates a vector for more sophisticated attacks within WordPress environments. Attackers can leverage this XSS flaw to execute persistent malicious scripts that can steal cookies, modify page content, redirect users to malicious sites, or even escalate privileges within the WordPress installation. The vulnerability affects WordPress sites using Pie Register plugin versions before 2.0.19, making it particularly concerning for organizations that may have delayed patching or maintained legacy systems. This flaw aligns with ATT&CK technique T1566, which covers credential access through the exploitation of web application vulnerabilities, and represents a common entry point for attackers seeking to establish persistent access to WordPress environments.
Organizations affected by this vulnerability should immediately implement the recommended mitigation strategies, which primarily involve upgrading to Pie Register version 2.0.19 or later where the XSS vulnerability has been patched. Additionally, administrators should consider implementing input validation and output encoding measures at the web application firewall level as an additional defensive layer. The patch for this vulnerability specifically addresses the improper handling of the invitation_code parameter by ensuring that all user input is properly sanitized before being processed or displayed. Security monitoring should include detection of suspicious invitation_code values and regular vulnerability scanning of WordPress installations to identify similar issues in other plugins or themes. The remediation process should also include reviewing existing user sessions and credentials, as the vulnerability could have been exploited to capture session information or steal user credentials through the execution of malicious scripts in users' browsers.