CVE-2022-2655 in Classified Listing Pro Plugin
Summary
by MITRE • 09/16/2022
The Classified Listing Pro WordPress plugin before 2.0.20 does not escape a generated URL before outputting it back in an attribute in an admin page, leading to a Reflected Cross-Site Scripting
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Analysis
by VulDB Data Team • 04/29/2025
The Classified Listing Pro WordPress plugin version 2.0.19 and earlier contains a critical cross-site scripting vulnerability that arises from improper output escaping in admin pages. This vulnerability specifically affects the plugin's handling of dynamically generated URLs within HTML attributes, creating an attack vector that allows malicious actors to inject arbitrary JavaScript code into the administrative interface. The flaw occurs when the plugin fails to properly sanitize URL parameters before embedding them into HTML attributes, particularly within the admin dashboard where privileged users interact with the plugin's functionality. This represents a classic reflected cross-site scripting vulnerability where malicious input is immediately reflected back to the user's browser without adequate sanitization or escaping mechanisms. The vulnerability is particularly concerning because it targets the administrative interface, which typically contains sensitive configuration options and user management capabilities, potentially allowing attackers to escalate privileges or gain unauthorized access to the WordPress installation.
The technical implementation of this vulnerability stems from the plugin's failure to apply proper HTML escaping routines to dynamically generated URLs before outputting them in attribute contexts. When an administrator navigates to pages within the plugin's admin interface, the system constructs URLs that may contain user-supplied or dynamic parameters that are not properly escaped before being embedded into HTML attributes such as href, src, or onclick handlers. This creates a scenario where an attacker could craft a malicious URL containing JavaScript code that gets executed when the admin user visits the affected page. The vulnerability is classified as a reflected XSS because the malicious payload is reflected back to the user through the plugin's own output mechanism rather than being stored in the database. According to CWE-79, this vulnerability directly maps to improper neutralization of input during web page generation, where the system fails to properly escape output that contains user-controllable data.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with potential access to administrative functions and sensitive data within the WordPress environment. An attacker who successfully exploits this vulnerability could inject malicious scripts that redirect administrators to phishing sites, steal session cookies, or execute commands on behalf of the administrator. The reflected nature of the vulnerability means that attackers need only convince an administrator to click on a malicious link containing the crafted payload, making this attack vector particularly dangerous in environments where administrators frequently navigate to external links or where the plugin is used in high-privilege contexts. This vulnerability could also enable attackers to perform actions such as modifying plugin settings, accessing user data, or even installing additional malware within the WordPress installation. The attack requires minimal user interaction beyond visiting the malicious page, making it particularly effective in social engineering campaigns where administrators are tricked into clicking compromised links.
Mitigation strategies for this vulnerability primarily focus on updating the plugin to version 2.0.20 or later, which contains the necessary patches to properly escape output before rendering URLs in admin pages. Organizations should immediately prioritize patching this vulnerability across all affected WordPress installations, particularly those running the Classified Listing Pro plugin in production environments. Additionally, administrators should implement proper input validation and output escaping mechanisms within their custom WordPress code, ensuring that all dynamic content is properly sanitized before being rendered in HTML contexts. Network-level protections such as web application firewalls can provide additional defense-in-depth, though they should not be relied upon as the sole mitigation strategy. Security monitoring should be enhanced to detect suspicious administrative activities that might indicate exploitation attempts, including unusual URL parameters or unexpected script executions. The vulnerability also highlights the importance of implementing proper security practices such as the principle of least privilege, where administrative functions are accessed only when necessary, and regular security audits of third-party plugins to ensure they meet current security standards. This vulnerability demonstrates the critical need for developers to follow secure coding practices and adhere to standards such as those outlined in the OWASP Top Ten, particularly focusing on input validation and output encoding to prevent XSS vulnerabilities in web applications.