CVE-2025-59431: Osgeo MapServer SQLi Vulnerability

CVE-2025-59431 Overview

CVE-2025-59431 is a Boolean-based SQL injection vulnerability affecting MapServer, a widely-used open-source platform for developing web-based Geographic Information System (GIS) applications. The vulnerability exists in the XML Filter Query directive's PropertyName parameter, where expression checking can be bypassed by introducing double quote characters. This allows attackers to manipulate backend database queries, potentially leading to unauthorized data access, data manipulation, or complete database compromise.

Critical Impact

Remote attackers can exploit this SQL injection vulnerability without authentication to bypass security controls and manipulate backend database queries, potentially exposing or corrupting sensitive GIS data.

Affected Products

• OSGeo MapServer versions prior to 8.4.1
• MapServer 8.4.0 and earlier releases
• Web-based GIS applications built on vulnerable MapServer versions

Discovery Timeline

• 2025-09-19 - CVE CVE-2025-59431 published to NVD
• 2025-10-08 - Last updated in NVD database

Technical Details for CVE-2025-59431

Vulnerability Analysis

This SQL injection vulnerability (CWE-89) exists in MapServer's XML Filter Query functionality. The PropertyName directive, which is used to specify database column names in WFS (Web Feature Service) filter queries, fails to properly sanitize input when double quote characters are introduced. This allows attackers to break out of the expected query context and inject arbitrary SQL commands.

The vulnerability is particularly concerning because it can be exploited remotely over the network without requiring authentication. Successful exploitation could allow an attacker to read sensitive data from the database, modify or delete data, or potentially execute administrative operations on the database system depending on the database permissions configured for the MapServer application.

Root Cause

The root cause of this vulnerability lies in insufficient input validation and improper expression checking within the PropertyName parameter handling. When double quote characters are introduced in the PropertyName value, the expression checking mechanism is bypassed, allowing malicious SQL syntax to pass through to the backend database. This is a classic example of improper input sanitization where special characters that have semantic meaning in SQL are not properly escaped or filtered.

Attack Vector

The attack vector is network-based, where an attacker sends specially crafted XML Filter Query requests to a vulnerable MapServer instance. By manipulating the PropertyName parameter with double quote characters, the attacker can inject Boolean-based SQL payloads that alter the logic of database queries. This Boolean-based SQL injection technique allows attackers to extract information by observing different application responses based on true/false conditions in the injected SQL.

A typical attack scenario involves:

1. Identifying a MapServer instance exposing WFS endpoints
2. Crafting an XML Filter Query with a malicious PropertyName value containing double quotes and SQL injection payloads
3. Observing application responses to determine if injected conditions evaluate as true or false
4. Systematically extracting database information through repeated queries

For detailed technical information about this vulnerability, refer to the GitHub Security Advisory.

Detection Methods for CVE-2025-59431

Indicators of Compromise

• Unusual XML Filter Query requests containing double quote characters in PropertyName parameters
• Database query logs showing unexpected SQL syntax or Boolean expressions
• Anomalous response times or error messages from WFS endpoints that may indicate SQL injection probing
• Increased failed or unusual requests to MapServer WFS services from single IP addresses

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect SQL injection patterns in XML Filter Query requests
• Monitor MapServer access logs for requests containing suspicious characters in PropertyName fields
• Enable database query logging and alert on queries containing unexpected Boolean expressions or SQL syntax
• Deploy network-based intrusion detection systems (IDS) with signatures for SQL injection attack patterns

Monitoring Recommendations

• Configure centralized logging for all MapServer instances and aggregate logs for security analysis
• Set up alerts for high volumes of requests to WFS endpoints or requests with unusual parameter patterns
• Monitor database performance metrics for anomalies that may indicate exploitation attempts
• Implement real-time monitoring of MapServer error logs for SQL-related error messages

How to Mitigate CVE-2025-59431

Immediate Actions Required

• Upgrade all MapServer installations to version 8.4.1 or later immediately
• Review MapServer access logs for signs of exploitation attempts
• Implement input validation at the application layer to filter double quote characters from PropertyName parameters as a temporary measure
• Restrict network access to MapServer WFS endpoints to trusted IP addresses where possible

Patch Information

OSGeo has released MapServer version 8.4.1 which addresses this SQL injection vulnerability. Organizations should update to this version as soon as possible. The patch information and security advisory can be found at the MapServer GitHub Security Advisory.

Workarounds

• Deploy a Web Application Firewall (WAF) in front of MapServer to filter requests containing SQL injection patterns
• Implement application-level input validation to reject PropertyName values containing double quote characters
• Use database account permissions following the principle of least privilege to limit the impact of successful SQL injection
• Consider temporarily disabling WFS Filter Query functionality if not required for business operations until patching is complete

# Example: Restrict MapServer WFS access via Apache configuration
# Add to MapServer virtual host configuration
<Location "/cgi-bin/mapserv">
    # Allow only trusted IP ranges
    Require ip 10.0.0.0/8 192.168.0.0/16
    
    # Block requests with suspicious patterns in query string
    RewriteEngine On
    RewriteCond %{QUERY_STRING} (PropertyName.*[\"]) [NC]
    RewriteRule .* - [F,L]
</Location>