CVE-2025-39504: GoodLayers Hotel SQL Injection Vulnerability

CVE-2025-39504 Overview

CVE-2025-39504 is a critical Blind SQL Injection vulnerability affecting the GoodLayers Hotel WordPress plugin. This vulnerability arises from improper neutralization of special elements used in SQL commands, allowing unauthenticated attackers to execute malicious SQL queries against the underlying database. The blind nature of this SQL injection means attackers can extract sensitive information through inference-based techniques without direct visibility of query results.

Critical Impact

Unauthenticated attackers can exploit this blind SQL injection to extract sensitive database contents including user credentials, payment information, and booking details from WordPress sites running the vulnerable GoodLayers Hotel plugin.

Affected Products

• GoodLayers Hotel WordPress Plugin versions up to and including 3.1.4
• WordPress installations with the gdlr-hotel plugin active
• All configurations of the affected plugin versions regardless of WordPress core version

Discovery Timeline

• 2025-05-23 - CVE-2025-39504 published to NVD
• 2025-05-23 - Last updated in NVD database

Technical Details for CVE-2025-39504

Vulnerability Analysis

This SQL Injection vulnerability (CWE-89) exists in the GoodLayers Hotel plugin due to insufficient input sanitization when processing user-supplied data in database queries. The plugin fails to properly escape or parameterize input before incorporating it into SQL statements, creating an opportunity for attackers to inject malicious SQL syntax.

As a blind SQL injection, the vulnerability does not return query results directly to the attacker. Instead, exploitation relies on observing application behavior differences (boolean-based) or time delays (time-based) to infer database contents character by character. This makes exploitation slower but equally dangerous for data extraction.

The network-accessible nature of this vulnerability combined with the lack of authentication requirements significantly increases its exploitability. Attackers can target any publicly accessible WordPress site running the vulnerable plugin version without needing valid credentials.

Root Cause

The root cause is improper input validation and the failure to use parameterized queries or prepared statements when constructing SQL queries. User-controlled input is concatenated directly into SQL statements without proper escaping or sanitization, allowing attackers to break out of the intended query context and inject arbitrary SQL commands.

WordPress provides functions like $wpdb->prepare() for safe database queries, but the vulnerable code paths in GoodLayers Hotel do not properly utilize these protections.

Attack Vector

The attack is conducted over the network against the WordPress front-end. Attackers craft HTTP requests containing SQL injection payloads in vulnerable parameters. The blind nature requires automated tools to efficiently extract data through boolean or time-based inference techniques.

A typical attack flow involves:

1. Identifying a vulnerable endpoint in the GoodLayers Hotel plugin
2. Crafting SQL injection payloads that cause measurable differences in application response
3. Using automated extraction techniques to retrieve database contents
4. Potentially escalating access by extracting WordPress administrator credentials

For detailed technical information about this vulnerability, refer to the Patchstack Vulnerability Report.

Detection Methods for CVE-2025-39504

Indicators of Compromise

• Unusual database query patterns or errors in web server and application logs
• HTTP requests containing SQL syntax characters (', ", ;, --, UNION, SELECT, SLEEP, BENCHMARK) in parameter values
• Increased response times on specific plugin endpoints indicating time-based injection attempts
• Web application firewall alerts for SQL injection patterns targeting WordPress installations

Detection Strategies

• Deploy web application firewall (WAF) rules to detect and block SQL injection patterns in requests to WordPress plugins
• Enable verbose database logging to identify suspicious query patterns and failed query attempts
• Monitor for automated scanning tools that may be probing for SQL injection vulnerabilities
• Implement intrusion detection system (IDS) rules to alert on SQL injection attack signatures

Monitoring Recommendations

• Configure real-time alerting for SQL injection detection events in WAF and IDS solutions
• Review WordPress and web server access logs for suspicious parameter patterns targeting the gdlr-hotel plugin
• Monitor database performance metrics for unusual query execution times that may indicate exploitation attempts
• Establish baseline plugin endpoint behavior to detect anomalous request patterns

How to Mitigate CVE-2025-39504

Immediate Actions Required

• Update the GoodLayers Hotel plugin to a patched version if available from the vendor
• If no patch is available, consider temporarily disabling the gdlr-hotel plugin until a fix is released
• Implement WAF rules to block SQL injection attempts targeting the vulnerable plugin
• Review database access logs for evidence of prior exploitation and assess potential data exposure

Patch Information

Organizations should monitor the GoodLayers Hotel plugin vendor for security updates. The Patchstack Vulnerability Report provides additional details on the vulnerability status and remediation guidance.

WordPress administrators should regularly check for plugin updates through the WordPress dashboard and prioritize security patches for critical vulnerabilities like SQL injection.

Workarounds

• Deploy a web application firewall with SQL injection detection capabilities to filter malicious requests
• Restrict access to the WordPress admin and plugin endpoints through IP-based access controls where feasible
• Implement database user privilege restrictions to limit the potential impact of SQL injection attacks
• Consider using a WordPress security plugin that provides virtual patching capabilities for known vulnerabilities

# Example: Restrict plugin access via .htaccess (Apache)
<IfModule mod_rewrite.c>
    RewriteEngine On
    # Block requests with common SQL injection patterns
    RewriteCond %{QUERY_STRING} (\%27)|(\')|(\-\-)|(\%23)|(#) [NC,OR]
    RewriteCond %{QUERY_STRING} (union)(.+)(select) [NC,OR]
    RewriteCond %{QUERY_STRING} (select)(.+)(from) [NC]
    RewriteRule ^wp-content/plugins/gdlr-hotel/.* - [F,L]
</IfModule>