CVE-2023-26567 in FreePBX
Summary
by MITRE • 04/26/2023
Sangoma FreePBX 1805 through 2302 (when obtained as a ,.ISO file) places AMPDBUSER, AMPDBPASS, AMPMGRUSER, and AMPMGRPASS in the list of global variables. This exposes cleartext authentication credentials for the Asterisk Database (MariaDB/MySQL) and Asterisk Manager Interface. For example, an attacker can make a /ari/asterisk/variable?variable=AMPDBPASS API call.
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Analysis
by VulDB Data Team • 11/10/2025
The vulnerability identified as CVE-2023-26567 affects Sangoma FreePBX versions ranging from 1805 through 2302 when installed via ISO file distribution. This represents a critical configuration flaw that exposes sensitive authentication credentials in cleartext format within the application's global variable namespace. The vulnerability stems from improper handling of database and manager interface credentials during the installation process, creating an attack surface that allows unauthorized access to core system components. The exposed credentials include AMPDBUSER, AMPDBPASS, AMPMGRUSER, and AMPMGRPASS variables that contain database username and password information for MariaDB/MySQL backend systems along with Asterisk Manager Interface credentials.
The technical exploitation of this vulnerability occurs through the Asterisk REST Interface (ARI) API endpoints, specifically targeting the /ari/asterisk/variable?variable=AMPDBPASS path. This API call allows attackers to directly retrieve the cleartext database password from the global variable scope without requiring additional authentication or privilege escalation. The flaw exists because the installation process fails to properly sanitize or isolate these credential variables, leaving them accessible through legitimate API interfaces that should only be available to authorized system administrators. This exposure creates a direct pathway for attackers to obtain database credentials and subsequently gain access to the underlying Asterisk database system, potentially leading to full system compromise.
The operational impact of this vulnerability is severe and multifaceted across multiple security domains. An attacker who successfully exploits this vulnerability can gain unauthorized access to the Asterisk Manager Interface which provides extensive control over the PBX system including the ability to make calls, monitor conversations, modify user accounts, and access sensitive telephony data. Additionally, database access through the exposed credentials allows for data exfiltration, modification of user configurations, and potential privilege escalation attacks. The cleartext exposure means that attackers can immediately leverage these credentials without needing to perform additional cracking or decryption processes, making the attack surface extremely dangerous for organizations relying on FreePBX for their telephony infrastructure. This vulnerability particularly affects small to medium businesses that may not have robust network segmentation or monitoring in place to detect such unauthorized API access attempts.
Organizations should implement immediate mitigations including disabling or restricting access to the Asterisk REST Interface API endpoints until proper credential handling procedures are implemented. The recommended approach involves ensuring that database and manager interface credentials are properly secured within the application configuration files rather than exposed in global variables accessible through API calls. Network segmentation should be implemented to restrict access to the ARI endpoints to only trusted administrative systems. Additionally, organizations should conduct comprehensive security audits of their FreePBX installations to verify that no other sensitive variables are exposed in similar ways. This vulnerability aligns with CWE-200 (Information Exposure) and CWE-798 (Use of Hard-coded Credentials) while mapping to ATT&CK techniques including T1566 (Phishing) for initial compromise and T1071.004 (Application Layer Protocol: SSH) for potential credential brute-forcing if additional attack vectors are present. Regular patching and version control of FreePBX installations is essential to prevent exploitation of this and similar credential exposure vulnerabilities.