Live Exposure Defense: From CVE to Confirmed Exposure in 12 Hours – See more

Back
New CVE Detected

CVE-2026-73665 – Unauthenticated RCE – FreePBX UCP (17.x) prior to 17.0.9

Be the first to know when new zero-days emerge:

Subscribe to Email Alerts
Subscribe to RSS Feed

Summary

CVE-2026-73665 is a critical, unauthenticated remote code execution vulnerability in the FreePBX User Control Panel (UCP) Node server, affecting FreePBX 17 installations running the UCP module prior to version 17.0.9. An authentication gap in the Socket.IO layer allows a network attacker with no credentials to reach the Asterisk Manager Interface (AMI) and inject commands that execute as the asterisk service user. The flaw carries a CVSS v4.0 base score of 9.3 (Critical).

Technical details

  • Root cause: The UCP Node server authenticates Socket.IO connections via a checkAuth middleware, but this middleware is only applied to the default Socket.IO namespace. Behavior changes in Socket.IO v4 mean custom namespaces are not covered by this middleware, leaving them unauthenticated.
  • Trigger conditions: An attacker only needs network access to the UCP Node server, which listens by default on TCP port 8001 (non-TLS) or 8003 (TLS).
  • Attack vector: By connecting directly to an unprotected custom Socket.IO namespace, an unauthenticated attacker can send crafted events that are relayed into Asterisk Manager Interface (AMI) actions. Insufficient sanitization of these events allows injection of carriage-return/newline characters, enabling arbitrary AMI command injection.
  • Impact: Successful exploitation results in arbitrary command execution with the privileges of the asterisk service account — full compromise of the PBX, with no authentication or user interaction required.

Affected software

  • FreePBX 17 — UCP (Unified Communications Portal) module, versions prior to 17.0.9
  • Fixed in UCP module version 17.0.9

Severity

  • CVSS v4.0 Base Score: 9.3 (Critical)
  • Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
  • CWE-862: Missing Authorization
  • Vendor-assigned urgency: Red (immediate action recommended)

Mitigation and recommended actions

  • Immediate: Upgrade the FreePBX UCP module to version 17.0.9 or later.
  • Network mitigation (if immediate patching is not possible): Restrict network access to UCP ports 8001/8003 using the FreePBX Firewall module, and enable the Responsive Firewall so UCP is only reachable from IPs that have successfully registered SIP endpoints with the PBX.
  • Access review: Audit and tighten the IP ranges assigned to Trusted and Local zones under Connectivity → Firewall → Networks to minimize exposure.
  • Verification: Confirm the patched state by checking for the <meta http-equiv="x-pjax-version" content="v17.0.9"> tag on the UCP login page.

References

Are you exposed?

Get a free report of your organization’s exposure to this CVE and threat

  • Mapping of all Assets with this Technology
  • Identification of potentially exposed assets to this CVE
  • Confirmation of verified exploitable assets
Get Exposure Report

How IONIX’s External Exposure Management Platform Detects and Validates
Zero-Days to Shrink MTTR

1

Map your entire attack surface (continously)

IONIX uses multi-factor discovery methods, including DNS analysis, certificate mapping, metadata inspection, and more, to automatically map every internet-facing asset across your environment. This includes cloud instances, third-party platforms, shadow IT, and even forgotten infrastructure that traditional tools miss.

2

Monitor for new CVEs

Dozens of threat intel feeds using agentic technology are continuously analyzed to detect the appearance of proof-of-concept code, exploit kits, and indicators of active targeting. IONIX goes further by applying AI to proactively evaluate whether emerging vulnerabilities are likely to be exploited, even before PoCs go public.

3

Identify Potential External Exposures

Not all CVEs matter. IONIX filters vulnerabilities by asking attacker-centric questions: Can it be reached from the internet? Does it require authentication? Is it being exploited in the wild? This dramatically reduces noise and focuses teams on threats that can actually be weaponized.

4

Create Safe, Scalable Exploit Validations

IONIX transforms real-world PoCs into safe, non-intrusive test payloads that can be run in production environments without disruption. These simulations are precisely targeted to the systems that are vulnerable, ensuring rapid validation without unnecessary load.

5

Execute Exploit Validations

By combining context about software stack, versioning, exposure status, and reachability, IONIX ensures that only the right payloads are executed against the right assets, maximizing efficiency and minimizing risk.

6

Drive Fast and Actionable Remediation

Results are routed through integrations with ticketing, SOAR, and SIEM tools. Issues are written in plain language, bundled into remediation clusters, and prioritized based on asset criticality, exploitability, and blast radius. This shortens mean time to remediation (MTTR) and empowers teams to act with confidence.

Are you exposed?

Get a free report of your organization’s exposure to this CVE and threat

  • Mapping of all Assets with this Technology
  • Identification of potentially exposed assets to this CVE
  • Confirmation of verified exploitable assets
Get Exposure Report
Close

Subscribe to Threat Center RSS

Copy/paste the link below into your preferred RSS reader or follow these instructions to subscribe to Slack alerts.

Open RSS feedSlack setup instructions

Close

Get Real-Time CVE Alerts to Your Email

Be the first to know when new zero-days emerge