CVE-2025-39501: GoodLayers Hostel SQL Injection Flaw

CVE-2025-39501 Overview

CVE-2025-39501 is a critical Blind SQL Injection vulnerability affecting the GoodLayers Hostel WordPress plugin. This vulnerability stems from improper neutralization of special elements used in SQL commands (CWE-89), allowing attackers to manipulate database queries through specially crafted input. Exploitation could enable unauthorized access to sensitive database contents, potentially compromising user data, authentication credentials, and other critical information stored in the WordPress database.

Critical Impact

Unauthenticated attackers can exploit this Blind SQL Injection vulnerability to extract sensitive database information from WordPress sites running vulnerable versions of the GoodLayers Hostel plugin.

Affected Products

• GoodLayers Hostel WordPress Plugin versions up to and including 3.1.2
• WordPress installations using the gdlr-hostel plugin
• All sites with vulnerable plugin versions regardless of WordPress core version

Discovery Timeline

• 2025-05-23 - CVE-2025-39501 published to NVD
• 2025-05-23 - Last updated in NVD database

Technical Details for CVE-2025-39501

Vulnerability Analysis

This vulnerability exists due to insufficient input validation and sanitization within the GoodLayers Hostel plugin. The plugin fails to properly neutralize user-supplied input before incorporating it into SQL queries, creating an injection point that attackers can exploit. As a Blind SQL Injection vulnerability, the attack does not return visible error messages or query results directly to the attacker. Instead, exploitation relies on inference-based techniques where attackers observe application behavior differences (time delays, response variations) to extract data character by character.

The network-accessible nature of this vulnerability means it can be exploited remotely without any prior authentication, significantly expanding the potential attack surface. Once exploited, an attacker gains read access to the entire WordPress database, which typically contains user credentials, personal information, configuration data, and potentially sensitive business information.

Root Cause

The root cause is improper input validation in the GoodLayers Hostel plugin's database query construction. User-controllable parameters are concatenated directly into SQL statements without proper sanitization, parameterized queries, or prepared statements. This allows malicious SQL syntax to break out of the intended query context and execute arbitrary database commands.

Attack Vector

This vulnerability can be exploited over the network without requiring authentication or user interaction. An attacker sends specially crafted HTTP requests to the vulnerable WordPress endpoint containing malicious SQL payloads. The plugin processes these requests and executes the injected SQL against the database.

The Blind SQL Injection technique works by injecting conditional statements that cause observable differences in application response. For example, an attacker might inject time-based payloads that cause database delays when conditions are true, or boolean-based payloads that produce different page responses. By systematically probing with these techniques, attackers can extract sensitive data including usernames, password hashes, and other confidential information stored in the database.

For detailed technical information about the vulnerability mechanism, refer to the Patchstack security advisory.

Detection Methods for CVE-2025-39501

Indicators of Compromise

• Unusual SQL-related entries in web server access logs containing characters such as ', ", --, UNION, SELECT, SLEEP(), or BENCHMARK()
• Abnormally slow database response times indicating time-based SQL injection attempts
• Unexpected database queries in MySQL/MariaDB slow query logs
• Error log entries referencing SQL syntax errors from the GoodLayers Hostel plugin

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block SQL injection patterns in HTTP requests
• Enable detailed logging on the WordPress installation and monitor for suspicious parameter values
• Implement database query auditing to identify anomalous query patterns or unauthorized data access attempts
• Use security scanning tools to identify vulnerable plugin versions across your WordPress installations

Monitoring Recommendations

• Configure real-time alerting for SQL injection attack signatures in WAF and IDS systems
• Monitor database connection logs for unusual query volumes or patterns from the web application
• Establish baseline metrics for database response times to detect time-based injection attacks
• Review WordPress plugin versions regularly using automated vulnerability scanning

How to Mitigate CVE-2025-39501

Immediate Actions Required

• Update the GoodLayers Hostel plugin to the latest patched version immediately
• Temporarily disable the gdlr-hostel plugin if an update is not yet available
• Review database access logs for signs of prior exploitation
• Rotate all database credentials and WordPress user passwords as a precaution
• Implement WAF rules to block common SQL injection payloads targeting your WordPress installation

Patch Information

Users should update the GoodLayers Hostel WordPress plugin to a version newer than 3.1.2 where the SQL injection vulnerability has been remediated. Check the Patchstack advisory for the latest patch information and update guidance. Ensure you are downloading updates only from official WordPress plugin repository sources.

Workarounds

• Disable the GoodLayers Hostel plugin until an official patch is available and verified
• Implement Web Application Firewall rules to filter SQL injection attempts targeting the affected endpoints
• Restrict access to WordPress admin and plugin functionality via IP allowlisting where feasible
• Consider using a WordPress security plugin with virtual patching capabilities to provide interim protection

# WordPress CLI command to check plugin version
wp plugin list --status=active --field=name,version | grep gdlr-hostel

# Disable vulnerable plugin temporarily
wp plugin deactivate gdlr-hostel

# Update plugin to latest version when patch is available
wp plugin update gdlr-hostel