CVE-2021-24196 in Social Slider Widget Plugin
Summary
by MITRE • 04/06/2021
The Social Slider Widget WordPress plugin before 1.8.5 allowed Authenticated Reflected XSS in the plugin settings page as the ‘token_error’ parameter can be controlled by users and it is directly echoed without being sanitized
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Analysis
by VulDB Data Team • 04/10/2021
The vulnerability identified as CVE-2021-24196 affects the Social Slider Widget WordPress plugin version 1.8.4 and earlier, representing a critical authenticated reflected cross-site scripting flaw that enables attackers with valid user credentials to execute malicious scripts within the context of a victim's browser. This vulnerability resides within the plugin's settings page where the token_error parameter is directly echoed back to users without proper sanitization or output encoding, creating an exploitable vector for cross-site scripting attacks.
The technical implementation of this vulnerability stems from improper input validation and output sanitization practices within the plugin's codebase. When an authenticated user accesses the plugin settings page, the application processes the token_error parameter which originates from user-controllable input sources and directly incorporates this data into the HTTP response without appropriate HTML escaping or sanitization measures. This flaw aligns with CWE-79 which specifically addresses cross-site scripting vulnerabilities arising from insufficient output encoding and improper input validation.
From an operational perspective, this vulnerability presents significant risks to WordPress installations utilizing the affected plugin version. An authenticated attacker with access to the WordPress admin panel can craft malicious payloads that will execute in the browser of any user who views the affected plugin settings page, including administrators. The reflected nature of this XSS means that the malicious script execution occurs in real-time as the page loads, making it particularly dangerous for privilege escalation attacks. Attackers could potentially leverage this vulnerability to steal session cookies, perform unauthorized actions on behalf of users, or redirect victims to malicious domains.
The impact extends beyond simple script execution as it can facilitate more sophisticated attacks within the WordPress environment. According to ATT&CK framework tactics, this vulnerability maps to T1566 (Phishing) and T1059 (Command and Scripting Interpreter) where attackers can use the XSS to establish persistent access or manipulate administrative functions. The authenticated nature of the vulnerability means that attackers do not need to compromise user credentials through traditional means, as they can leverage existing administrative access to deploy malicious scripts.
Mitigation strategies for CVE-2021-24196 include immediate patching to version 1.8.5 or later where the plugin developers have implemented proper input sanitization and output encoding for the token_error parameter. Additionally, administrators should implement network-level protections such as web application firewalls that can detect and block suspicious parameter patterns, while also monitoring for unusual activity in the plugin settings pages. Security hardening practices should include regular plugin updates, implementing the principle of least privilege for user accounts, and conducting periodic security audits of WordPress installations. The vulnerability demonstrates the critical importance of proper input validation and output encoding practices in preventing cross-site scripting attacks, particularly in administrative interfaces where elevated privileges can amplify the impact of such flaws.