CVE-2026-28284: FreePBX Logfiles Module SQLi Vulnerability

CVE-2026-28284 Overview

CVE-2026-28284 is a high-severity SQL Injection vulnerability affecting FreePBX, an open source IP PBX platform. The vulnerability exists in the FreePBX logfiles module, which contains several authenticated SQL injection flaws that could allow attackers with valid credentials to manipulate database queries and potentially compromise the underlying system.

Critical Impact

Authenticated attackers can exploit SQL injection vulnerabilities in the FreePBX logfiles module to read, modify, or delete database contents, potentially leading to complete system compromise.

Affected Products

• FreePBX versions prior to 16.0.10
• FreePBX versions prior to 17.0.5
• FreePBX logfiles module (vulnerable component)

Discovery Timeline

• 2026-03-05 - CVE-2026-28284 published to NVD
• 2026-03-05 - Last updated in NVD database

Technical Details for CVE-2026-28284

Vulnerability Analysis

This vulnerability falls under CWE-89 (Improper Neutralization of Special Elements used in an SQL Command), commonly known as SQL Injection. The FreePBX logfiles module fails to properly sanitize user-supplied input before incorporating it into SQL queries, allowing authenticated users to inject malicious SQL statements.

SQL injection vulnerabilities in administrative modules like logfiles are particularly dangerous because they can be leveraged to extract sensitive configuration data, modify system settings, or escalate privileges within the PBX infrastructure. Given that FreePBX manages telecommunications infrastructure, successful exploitation could compromise call routing, voicemail systems, and potentially expose sensitive communication metadata.

Root Cause

The root cause is improper input validation and sanitization within the FreePBX logfiles module. User-controlled parameters are directly concatenated into SQL queries without adequate escaping or parameterization, violating secure coding practices for database interactions. This allows attackers to break out of the intended query structure and execute arbitrary SQL commands.

Attack Vector

The attack requires network access and valid authentication credentials to the FreePBX administrative interface. Once authenticated, an attacker can craft malicious input through the logfiles module interface that gets incorporated into backend SQL queries. The vulnerability has a network-based attack vector with low complexity, though it requires high privileges (authenticated access) to exploit.

Exploitation typically involves crafting specially formatted input strings containing SQL metacharacters and commands that alter the logic of the underlying database queries. This could enable data exfiltration through UNION-based injection, blind SQL injection for data inference, or potentially command execution if database features like xp_cmdshell (SQL Server) or INTO OUTFILE (MySQL) are available.

Detection Methods for CVE-2026-28284

Indicators of Compromise

• Unusual or malformed requests to the FreePBX logfiles module endpoints containing SQL metacharacters (', ", ;, --, /*)
• Database error messages appearing in web server logs indicating SQL syntax errors
• Unexpected database queries or access patterns from the FreePBX application
• Evidence of data exfiltration or unauthorized database modifications

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block SQL injection patterns in requests to FreePBX
• Enable detailed logging on the FreePBX web server and database to capture suspicious query attempts
• Implement database activity monitoring to detect anomalous queries originating from the FreePBX application
• Use SentinelOne's application control and behavioral analysis to identify exploitation attempts

Monitoring Recommendations

• Monitor FreePBX administrative access logs for unusual activity patterns or repeated authentication attempts
• Set up alerts for database errors indicating potential SQL injection exploitation
• Review network traffic to and from FreePBX servers for signs of data exfiltration
• Implement real-time monitoring of database query logs for injection patterns

How to Mitigate CVE-2026-28284

Immediate Actions Required

• Upgrade FreePBX to version 16.0.10 or later (for 16.x branch) immediately
• Upgrade FreePBX to version 17.0.5 or later (for 17.x branch) immediately
• Restrict network access to FreePBX administrative interfaces to trusted IP addresses only
• Review and audit user accounts with administrative access to minimize attack surface
• Implement additional WAF protections while planning the upgrade

Patch Information

FreePBX has addressed this vulnerability in versions 16.0.10 and 17.0.5. Organizations should update to these patched versions as soon as possible. For detailed patch information and security advisories, refer to the FreePBX Security Advisory on GitHub.

Workarounds

• Implement network segmentation to isolate FreePBX servers from untrusted networks
• Deploy a Web Application Firewall (WAF) with SQL injection detection rules in front of FreePBX
• Enforce strict access controls and multi-factor authentication for administrative access
• Disable or restrict access to the logfiles module if not operationally required until patching is complete

# Example: Restrict FreePBX admin access to specific IP addresses using iptables
iptables -A INPUT -p tcp --dport 443 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP

# Enable enhanced logging for FreePBX (httpd configuration)
# Add to /etc/httpd/conf.d/freepbx.conf
# CustomLog /var/log/httpd/freepbx_access.log combined
# ErrorLog /var/log/httpd/freepbx_error.log