FreePBX 2025: Critical SQL Injection & Authentication Bypass Threatens Telecom Security
Executive Summary
In September 2025, researchers from Horizon3.ai disclosed multiple severe vulnerabilities in FreePBX, an open-source private branch exchange (PBX) platform. These flaws, notably including a critical authentication bypass (CVE-2025-61675) and SQL injection issues, enabled remote code execution under certain configurations. Attackers could exploit these weaknesses to upload malicious files, bypass authentication controls, and potentially gain full system access. The vulnerabilities were responsibly reported to project maintainers, prompting urgent security patches and advisories to all FreePBX users. Organizations using affected versions faced significant risks, ranging from service disruption to compromise of sensitive communications and voicemail data.
This incident highlights the persistent threat posed by application-layer vulnerabilities in widely deployed open-source communications platforms. The rise of telephony-based attacks and increasingly sophisticated exploitation tactics underscore the need for proactive patch management, rigorous code auditing, and supply chain security in telecom infrastructure.
Why This Matters Now
Telecommunication platforms like FreePBX are integral to enterprise operations, and unpatched vulnerabilities expose critical business communications to external threats. The urgent need to address these flaws stems from an uptick in exploitation attempts of PBX platforms, regulatory pressure to secure sensitive data in transit, and the risk of lateral movement from compromised systems.
Attack Path Analysis
Attackers exploited a FreePBX authentication bypass and SQL injection vulnerability to gain initial access to an exposed PBX server. After compromise, the attackers leveraged the flaws to escalate privileges, obtaining administrative control of the PBX application. Using these privileges, they moved laterally or accessed other internal systems due to insufficient east-west traffic controls. Subsequently, the threat actors established command and control channels with the compromised server for persistence and management, possibly by uploading webshells or reverse shells. From there, they exfiltrated sensitive call data or configuration files using outbound connections. Finally, they could cause business disruption by modifying PBX settings, deleting data, or using the foothold for further malicious operations.
Kill Chain Progression
Initial Compromise
Description
The attacker exploited the FreePBX authentication bypass and SQL injection (CVE-2025-61675) to gain unauthorized access to the PBX management portal.
Related CVEs
CVE-2025-61675
CVSS 8.6Authenticated SQL injection vulnerabilities in FreePBX Endpoint Manager allow users to execute arbitrary SQL queries, potentially accessing sensitive data or modifying database contents.
Affected Products:
Sangoma FreePBX Endpoint Manager – < 16.0.92, < 17.0.6
Exploit Status:
no public exploitCVE-2025-61678
CVSS 8.6Authenticated arbitrary file upload vulnerability in FreePBX Endpoint Manager's fwbrand parameter allows users to upload files to attacker-controlled paths, potentially leading to remote code execution.
Affected Products:
Sangoma FreePBX Endpoint Manager – < 16.0.92, < 17.0.6
Exploit Status:
no public exploitCVE-2025-66039
CVSS 9.3Authentication bypass in FreePBX Endpoint Manager when AUTHTYPE is set to 'webserver' allows unauthorized access by providing an arbitrary Authorization header.
Affected Products:
Sangoma FreePBX Endpoint Manager – < 16.0.44, < 17.0.23
Exploit Status:
no public exploit
MITRE ATT&CK® Techniques
Exploit Public-Facing Application
Valid Accounts
Exploitation for Defense Evasion
Process Injection
Container Administration Command
Exfiltration Over Alternative Protocol
Forge Web Credentials
Potential Compliance Exposure
Mapping incident impact across multiple compliance frameworks.
PCI DSS 4.0 – Security of Public-Facing Web Applications
Control ID: 6.2.2
NYDFS 23 NYCRR 500 – Cybersecurity Policy
Control ID: 500.03
NIS2 Directive – Technical and Organisational Measures (Vulnerability Management)
Control ID: Article 21(2)(a)
CISA Zero Trust Maturity Model 2.0 – Enforce Strong Authentication and Least Privilege
Control ID: Identity Pillar: Least Privilege
DORA (Digital Operational Resilience Act) – ICT Risk Management (Vulnerability Management)
Control ID: Article 9(2)
Sector Implications
Industry-specific impact of the vulnerabilities, including operational, regulatory, and cloud security risks.
Telecommunications
FreePBX SQLi and authentication bypass vulnerabilities directly threaten PBX systems, enabling RCE attacks on critical voice infrastructure and customer communications.
Information Technology/IT
IT service providers using FreePBX face severe risks from authentication bypass and file upload flaws, potentially compromising client networks and services.
Health Care / Life Sciences
Healthcare organizations using FreePBX for communications face HIPAA compliance violations and patient data exposure through critical authentication bypass vulnerabilities.
Financial Services
Financial institutions with FreePBX deployments risk regulatory non-compliance and sensitive data breaches through SQL injection and remote code execution attacks.
Sources
- FreePBX Patches Critical SQLi, File-Upload, and AUTHTYPE Bypass Flaws Enabling RCEhttps://thehackernews.com/2025/12/freepbx-authentication-bypass-exposed.htmlVerified
- CVE-2025-61675 Detailhttps://nvd.nist.gov/vuln/detail/CVE-2025-61675Verified
- CVE-2025-61678 Detailhttps://nvd.nist.gov/vuln/detail/CVE-2025-61678Verified
- CVE-2025-66039 Detailhttps://nvd.nist.gov/vuln/detail/CVE-2025-66039Verified
Frequently Asked Questions
Cloud Native Security Fabric Mitigations and ControlsCNSF
Implementing zero trust segmentation, microsegmentation, and tightened east-west traffic controls, together with outbound egress policy enforcement and real-time anomaly detection, would significantly curtail an attacker's ability to move laterally, establish C2, and exfiltrate sensitive data in cloud-connected PBX environments.
Control: Cloud Firewall (ACF)
Mitigation: Blocked unauthorized inbound connections to application services.
Control: Threat Detection & Anomaly Response
Mitigation: Alerted on suspicious privilege changes within workloads.
Control: Zero Trust Segmentation
Mitigation: Contained the attacker's movement to the compromised workload.
Control: Egress Security & Policy Enforcement
Mitigation: Blocked or alerted on unauthorized outbound C2 attempts.
Control: Encrypted Traffic (HPE) & Egress Security
Mitigation: Monitored, encrypted, and restricted data exfiltration attempts.
Detected and responded to destructive configuration activity.
Impact at a Glance
Affected Business Functions
- Telephony Services
- Customer Support
Estimated downtime: 3 days
Estimated loss: $50,000
Potential exposure of sensitive customer call records and internal communications.
Recommended Actions
Key Takeaways & Next Steps
- • Deploy least privilege and zero trust segmentation controls around PBX and other sensitive workloads to limit the blast radius of web-facing vulnerabilities.
- • Implement strict east-west network segmentation and microsegmentation to prevent lateral movement post-compromise.
- • Enforce outbound egress policies and traffic filtering at workload and subnet boundaries to detect and block unauthorized C2 and data exfiltration.
- • Continuously monitor for anomalous privilege escalation, C2 channels, and destructive behavior using real-time threat detection tools.
- • Encrypt all sensitive data in transit and ensure centralized, cloud-native visibility into workload traffic and administrative actions.
