CVE-2025-39587: Cost Calculator Builder SQL Vulnerability

CVE-2025-39587 Overview

CVE-2025-39587 is a critical SQL Injection vulnerability discovered in the Stylemix Cost Calculator Builder WordPress plugin. This vulnerability allows unauthenticated attackers to inject malicious SQL commands through improperly neutralized user input, potentially leading to unauthorized database access, data exfiltration, and compromise of the underlying WordPress installation.

Critical Impact

Unauthenticated SQL Injection vulnerability enables attackers to extract sensitive database contents, including user credentials, payment information, and other confidential data stored in WordPress databases.

Affected Products

• Cost Calculator Builder plugin versions through 3.2.65
• WordPress installations running vulnerable Cost Calculator Builder versions
• Any website utilizing the Cost Calculator Builder for pricing calculations

Discovery Timeline

• 2025-04-17 - CVE-2025-39587 published to NVD
• 2025-04-17 - Last updated in NVD database

Technical Details for CVE-2025-39587

Vulnerability Analysis

This SQL Injection vulnerability (CWE-89) exists within the Cost Calculator Builder plugin, a popular WordPress plugin used for creating cost estimation forms. The flaw stems from improper neutralization of special characters in user-supplied input before incorporating it into SQL queries. Since the vulnerability can be exploited over the network without authentication and affects the confidentiality of the hosting environment beyond the vulnerable component itself, it poses a significant threat to WordPress installations.

Successful exploitation allows attackers to manipulate backend database queries, potentially extracting the entire database contents including WordPress user tables, plugin configurations, customer data, and any sensitive information stored by the Cost Calculator Builder or other plugins sharing the same database.

Root Cause

The root cause of CVE-2025-39587 is the failure to properly sanitize, escape, or parameterize user input before including it in SQL statements. The Cost Calculator Builder plugin versions through 3.2.65 do not adequately validate input parameters, allowing specially crafted SQL syntax to be interpreted as part of the database query rather than as literal data. This is a classic example of a first-order SQL injection where malicious input directly influences query execution.

Attack Vector

The attack is network-accessible and requires no authentication or user interaction. An attacker can craft malicious HTTP requests containing SQL injection payloads targeting vulnerable plugin endpoints. The payloads are processed by the plugin's backend PHP code and passed directly to the database engine, enabling:

• Data Extraction: Using UNION-based or blind SQL injection techniques to retrieve database contents
• Authentication Bypass: Manipulating queries to bypass login mechanisms
• Data Manipulation: Modifying or deleting database records
• Privilege Escalation: Creating new administrative users or elevating existing accounts

Due to the lack of verified code examples, readers should consult the Patchstack Security Advisory for detailed technical analysis of the vulnerable code paths and exploitation techniques.

Detection Methods for CVE-2025-39587

Indicators of Compromise

• Unusual database queries in MySQL/MariaDB logs containing SQL injection syntax such as UNION SELECT, OR 1=1, or -- comment markers
• Web server access logs showing requests to Cost Calculator Builder endpoints with encoded special characters or abnormally long parameter values
• Unexpected database modifications, new user accounts, or changes to existing admin credentials
• Error messages in application logs indicating SQL syntax errors from malformed injection attempts

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block common SQL injection patterns targeting WordPress plugins
• Enable and monitor WordPress database query logging for suspicious patterns
• Deploy file integrity monitoring on the WordPress installation to detect unauthorized modifications
• Utilize SentinelOne's application visibility capabilities to identify exploitation attempts against vulnerable WordPress components

Monitoring Recommendations

• Configure real-time alerting for SQL error patterns in web application logs
• Monitor for anomalous outbound data transfers that could indicate database exfiltration
• Track HTTP POST requests to Cost Calculator Builder AJAX handlers for injection payloads
• Implement baseline behavior analysis for database query patterns to detect deviations

How to Mitigate CVE-2025-39587

Immediate Actions Required

• Update Cost Calculator Builder to a version newer than 3.2.65 immediately
• Audit WordPress user accounts for unauthorized additions or privilege changes
• Review database logs for evidence of prior exploitation attempts
• Consider temporarily disabling the Cost Calculator Builder plugin until patched
• Implement WAF rules to block SQL injection attempts as a defense-in-depth measure

Patch Information

Stylemix has addressed this vulnerability in versions released after 3.2.65. Administrators should update to the latest available version through the WordPress plugin repository. The patch implements proper input sanitization and parameterized queries to prevent SQL injection attacks.

For detailed patch information and timeline, refer to the Patchstack vulnerability database entry.

Workarounds

• Implement server-level input filtering to block requests containing SQL injection metacharacters
• Restrict access to WordPress admin and AJAX endpoints using IP allowlisting where feasible
• Deploy a Web Application Firewall with SQL injection detection rules enabled
• Consider implementing database user privilege separation to limit the impact of successful injection

# WordPress plugin update via WP-CLI
wp plugin update cost-calculator-builder --version=latest

# Verify plugin version after update
wp plugin list --name=cost-calculator-builder --format=table