CVE-2021-24366 in Admin Columns Free Plugin
Summary
by MITRE • 06/22/2021
The Admin Columns Free WordPress plugin before 4.3 and Admin Columns Pro WordPress plugin before 5.5.1, rendered input on the posted pages with improper input validation on the value passed into the field 'Label' parameter, by taking this as an advantage an authenticated attacker can supply a crafted arbitrary script and execute it.
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Analysis
by VulDB Data Team • 05/06/2025
The vulnerability CVE-2021-24366 represents a critical cross-site scripting flaw affecting the Admin Columns WordPress plugins, specifically targeting versions prior to 4.3 for the free edition and 5.5.1 for the Pro edition. This security weakness stems from inadequate input validation mechanisms within the plugin's administrative interface, where user-supplied data intended for the 'Label' parameter is not properly sanitized before being rendered on web pages. The vulnerability exists in the plugin's handling of user input within the administrative dashboard context, creating an exploitable condition that allows malicious actors to inject and execute arbitrary scripts within the browser of authenticated users.
The technical exploitation of this vulnerability occurs through a classic cross-site scripting attack vector where an authenticated attacker with sufficient privileges can manipulate the Label parameter to inject malicious JavaScript code. When the plugin processes this crafted input and renders it on administrative pages, the malicious script executes within the context of the victim user's browser session. This presents a significant risk as the attacker can leverage this capability to perform actions on behalf of the authenticated user, potentially escalating privileges or accessing sensitive administrative functions. The vulnerability is classified as a CWE-79 Improper Neutralization of Input During Web Page Generation, which directly maps to the standard definition of cross-site scripting vulnerabilities where untrusted data is improperly incorporated into web page content.
The operational impact of CVE-2021-24366 extends beyond simple script execution, as it enables attackers to compromise the entire WordPress administrative environment. An authenticated attacker can use this vulnerability to establish persistent access, manipulate content, modify user permissions, or even install malicious plugins to maintain control over the compromised site. The attack requires minimal privileges since only authenticated access is needed, making it particularly dangerous in environments where administrative credentials might be compromised through other means. This vulnerability particularly affects WordPress sites that rely heavily on the Admin Columns plugin for managing content and user interfaces, as it essentially provides a backdoor for attackers to execute arbitrary commands within the administrative context.
Mitigation strategies for CVE-2021-24366 primarily focus on immediate plugin updates to versions 4.3 and 5.5.1 respectively, which contain the necessary input validation fixes. Administrators should also implement additional security measures such as restricting administrative privileges to only essential personnel and monitoring user activities for suspicious behavior patterns. The vulnerability aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter: JavaScript, as it enables attackers to execute JavaScript code within the browser context of authenticated users. Regular security audits of installed plugins, implementation of web application firewalls, and maintaining up-to-date security practices including multi-factor authentication for administrative accounts significantly reduce the risk exposure associated with this vulnerability. Organizations should also consider implementing content security policies to further limit the execution of unauthorized scripts within their WordPress environments.