CVE-2021-47951 Overview
CVE-2021-47951 is a stored cross-site scripting (XSS) vulnerability in the WordPress Picture Gallery plugin version 1.4.2. The flaw resides in the Edit Content URL field within the plugin's Access Control settings. Authenticated attackers can inject JavaScript payloads that the plugin persists in the WordPress database. When an administrator or user triggers the affected functionality, the browser renders the stored payload in the context of the site origin. Successful exploitation enables session hijacking, credential theft, and administrative account takeover. The issue is classified under CWE-79 — Improper Neutralization of Input During Web Page Generation.
Critical Impact
Authenticated attackers can plant persistent JavaScript in plugin settings, leading to session theft and privileged account compromise when the payload executes in an admin browser.
Affected Products
- WordPress Picture Gallery plugin version 1.4.2
- WordPress sites with the Picture Gallery plugin installed and Access Control enabled
- Administrative users interacting with the plugin's Edit Content URL setting
Discovery Timeline
- 2026-05-10 - CVE-2021-47951 published to NVD
- 2026-05-12 - Last updated in NVD database
Technical Details for CVE-2021-47951
Vulnerability Analysis
The vulnerability is a stored XSS [CWE-79] in the WordPress Picture Gallery plugin 1.4.2. The plugin accepts user-supplied input in the Edit Content URL field of its Access Control settings without applying output encoding or input sanitization. The submitted value is written to the WordPress options table and later rendered in HTML contexts without escaping. An authenticated user with permission to access the plugin configuration page can embed arbitrary JavaScript. The payload executes whenever an administrator views the affected admin screen or the plugin renders the stored URL. See the VulnCheck Advisory on XSS and Exploit-DB #50187 for additional context.
Root Cause
The plugin treats the Edit Content URL value as trusted data. It does not invoke WordPress sanitization helpers such as esc_url_raw() on input or esc_attr() and esc_html() on output. This allows raw <script> tags and event handlers to persist in plugin options and reach the DOM intact.
Attack Vector
An authenticated user navigates to the Picture Gallery plugin's Access Control configuration page. The attacker submits a JavaScript payload, such as a <script> tag containing code that exfiltrates document.cookie to an attacker-controlled host, in the Edit Content URL field. The value is stored in the database. Each time an administrator loads the affected page, the script runs with the privileges of the active session. Refer to the WordPress Plugin Page and the linked Exploit-DB entry for proof-of-concept details. No verified sanitized exploit code is published here.
Detection Methods for CVE-2021-47951
Indicators of Compromise
- Plugin option values in the WordPress wp_options table containing <script>, onerror=, onload=, or javascript: strings tied to the Picture Gallery plugin.
- Outbound HTTP requests from administrator browsers to unfamiliar domains immediately after loading plugin admin pages.
- New WordPress administrator accounts or unexpected role changes following plugin configuration access.
Detection Strategies
- Inspect plugin option rows associated with picture-gallery for HTML tags or JavaScript URI schemes in stored URL fields.
- Review WordPress audit logs for update_option events tied to the Picture Gallery plugin by non-administrator accounts.
- Deploy a Web Application Firewall (WAF) rule that flags HTML or script characters in plugin settings POST bodies.
Monitoring Recommendations
- Alert on Content Security Policy (CSP) violation reports originating from /wp-admin/ pages.
- Monitor for anomalous outbound traffic from administrator workstations after WordPress admin sessions.
- Track plugin file integrity and configuration changes through file integrity monitoring on wp-content/plugins/picture-gallery/.
How to Mitigate CVE-2021-47951
Immediate Actions Required
- Uninstall or deactivate the WordPress Picture Gallery plugin version 1.4.2 until a fixed release is confirmed.
- Audit the wp_options table for malicious payloads stored by the plugin and remove any tainted entries.
- Rotate WordPress administrator passwords and invalidate active sessions to mitigate possible credential theft.
Patch Information
No vendor patch is referenced in the available CVE data. Consult the WordPress Plugin Page for current version availability and changelog entries. If no patched version is published, remove the plugin and select an actively maintained alternative.
Workarounds
- Restrict plugin configuration access to trusted administrators by tightening WordPress role capabilities.
- Apply a strict Content Security Policy that blocks inline scripts in the /wp-admin/ interface.
- Place WordPress behind a WAF configured to strip HTML and JavaScript from plugin settings parameters.
# Configuration example: disable and remove the vulnerable plugin via WP-CLI
wp plugin deactivate picture-gallery
wp plugin delete picture-gallery
# Audit stored options for injected script content
wp db query "SELECT option_id, option_name FROM wp_options WHERE option_value LIKE '%<script%' OR option_value LIKE '%javascript:%';"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
