framework: Improper Authentication
CVE-2025-66039 is a critical-severity improper authentication vulnerability in framework from FreePBX, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected framework versions: < 16.0.44; >= 17.0.1, < 17.0.23. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 3.34% chance of exploitation within 30 days, higher than 89% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Freepbx to 16.0.44 or 17.0.23, whichever matches your release line, or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| FreePBX | framework | < 16.0.44; >= 17.0.1, < 17.0.23 | Not stated |
| Sangoma | Freepbx | before 16.0.44; 17.0.1 up to, but not including, 17.0.23 | 16.0.44, 17.0.23 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 9.3 | Critical | CNA (github.com) |
| CVSS 3.1 | 9.8 | Critical | NVD |
Official description
FreePBX Endpoint Manager is a module for managing telephony endpoints in FreePBX systems. Versions are vulnerable to authentication bypass when the authentication type is set to "webserver." When providing an Authorization header with an arbitrary value, a session is associated with the target user regardless of valid credentials. This issue is fixed in versions 16.0.44 and 17.0.23.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Authentication
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
How developers prevent this class of flaw
- Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Patches and release notes
Other vulnerabilities in framework
- 7.8 High severity
- 7.5 High severity
- 8.8 High severity
Recent Improper Authentication vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 10.0 Critical severity
- 10.0 Critical severity
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