CVE-2025-53306: WP Forum Server SQLi Vulnerability

CVE-2025-53306 Overview

CVE-2025-53306 is a SQL Injection vulnerability affecting the lucidcrew WP Forum Server WordPress plugin (forum-server). The flaw stems from improper neutralization of special elements used in SQL commands [CWE-89]. All plugin versions up to and including 1.8.2 are affected.

An authenticated attacker with high privileges can inject arbitrary SQL into backend database queries. Successful exploitation enables disclosure of confidential data stored across the WordPress database and partial impact to availability. The scope is changed, meaning the vulnerability impacts resources beyond the vulnerable component itself.

Critical Impact
Authenticated attackers can extract sensitive data from the WordPress database and degrade forum availability through crafted SQL payloads.

Affected Products

lucidcrew WP Forum Server (forum-server) plugin for WordPress
All versions from initial release through 1.8.2
WordPress sites running the vulnerable plugin with privileged user accounts

Discovery Timeline

2025-06-27 - CVE-2025-53306 published to NVD
2026-04-23 - Last updated in NVD database

Technical Details for CVE-2025-53306

Vulnerability Analysis

The vulnerability resides in the WP Forum Server plugin's handling of user-supplied input passed to SQL queries. The plugin fails to properly sanitize or parameterize input before concatenating it into database statements. This allows an attacker to break out of the intended query context and inject arbitrary SQL clauses.

Exploitation requires network access to the WordPress site and high-privilege authentication. Because the scope is changed, the injected SQL can access data outside the security boundary of the plugin itself, including content owned by other WordPress components and users.

The primary impact is confidentiality loss through database exfiltration. Availability is also affected at a lower level, since malicious queries can degrade database performance or corrupt forum data. Integrity is not directly impacted according to the published CVSS vector.

Root Cause

The root cause is improper neutralization of special elements in SQL commands [CWE-89]. The plugin constructs SQL queries by concatenating untrusted input rather than using prepared statements with parameter binding through the WordPress $wpdb->prepare() API. Special characters such as single quotes, comments (--), and statement separators are not escaped or rejected.

Attack Vector

An authenticated attacker with administrative or equivalent privileges sends a crafted HTTP request to a vulnerable plugin endpoint. The injected SQL payload is concatenated into a backend query and executed against the WordPress database. The attacker then retrieves sensitive data through error-based, union-based, or blind injection techniques.

The vulnerability is described in the Patchstack WordPress Vulnerability database. No public proof-of-concept exploit has been published, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

Detection Methods for CVE-2025-53306

Indicators of Compromise

Unexpected SQL syntax such as UNION SELECT, OR 1=1, or SQL comment sequences in web server access logs targeting forum-server plugin endpoints
Anomalous database queries originating from the WordPress process with unusually large result sets or references to wp_users and wp_usermeta tables
Authenticated requests from privileged accounts containing URL-encoded SQL metacharacters (%27, %2D%2D, %23)

Detection Strategies

Inspect WordPress access logs for HTTP requests to forum-server plugin endpoints containing SQL keywords or encoded special characters
Enable MySQL general query logging or slow query logging to identify malformed or attacker-influenced statements originating from the plugin
Deploy a web application firewall with SQL injection signatures tuned for WordPress plugin parameters

Monitoring Recommendations

Monitor privileged user activity for unusual forum administration actions correlated with database query spikes
Alert on database errors logged by WordPress (WPDB) that reference syntax failures, which often indicate injection probing
Track outbound data volumes from the database tier to detect large exfiltration attempts following injection

How to Mitigate CVE-2025-53306

Immediate Actions Required

Identify all WordPress instances running the WP Forum Server (forum-server) plugin at version 1.8.2 or earlier
Disable the plugin if it is not in active use until a patched version is installed
Review WordPress audit logs for suspicious actions by administrator or high-privilege accounts
Rotate database credentials and WordPress administrator passwords if exploitation is suspected

Patch Information

At the time of NVD publication, the advisory lists affected versions through 1.8.2 with no fixed version specified in the CVE record. Site administrators should consult the Patchstack advisory and the WordPress.org plugin repository for the latest patched release and upgrade immediately when available.

Workarounds

Restrict access to WordPress administrative roles and enforce least privilege for users who interact with forum administration
Place the WordPress site behind a web application firewall configured to block SQL injection patterns against plugin endpoints
Apply virtual patching rules through a WAF or security plugin to filter SQL metacharacters in requests targeting forum-server parameters
Enable multi-factor authentication on all privileged WordPress accounts to reduce the risk of credential abuse leading to exploitation

bash

# Example WordPress CLI commands to identify and disable the vulnerable plugin
wp plugin list --name=forum-server --fields=name,status,version
wp plugin deactivate forum-server