api: Privilege Context Switching Error
CVE-2025-55210 is a high-severity privilege context switching error vulnerability in api from FreePBX, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected api versions: >= 15.0.1alpha1, < 16.0.17; >= 17.0.0, < 17.0.5. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.35% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Freepbx to 16.0.17 or 17.0.5, whichever matches your release line, or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| FreePBX | api | >= 15.0.1alpha1, < 16.0.17; >= 17.0.0, < 17.0.5 | Not stated |
| Sangoma | Freepbx | 16.0.2 up to, but not including, 16.0.17; 17.0.1 up to, but not including, 17.0.5 | 16.0.17, 17.0.5 |
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
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- LowA basic user account is enough.
- 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:H/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 2.0 | Low | CNA (github.com) |
| CVSS 3.1 | 7.5 | High | NVD |
Official description
FreePBX is an open-source web-based graphical user interface (GUI) that manages Asterisk. Prior to 17.0.5 and 16.0.17, FreePBX module api (PBX API) is vulnerable to privilege escalation by authenticated users with REST/GraphQL API access. This vulnerability allows an attacker to forge a valid JWT with full access to the REST and GraphQL APIs on a FreePBX that they've already connected to, possibly as a lower privileged user. The JWT is signed using the api-oauth.key private key. An attacker can generate their own token if they possess this key (e.g., by accessing an affected instance), and specify any scopes they wish (e.g., rest, gql), bypassing traditional authorization checks. However, FreePBX enforces that the jti (JWT ID) claim must exist in the database (api_access_tokens table in the asterisk MySQL database) in order for the token to be accepted. Therefore, the attacker must know a jti value that already exists on the target instance. This vulnerability is fixed in 17.0.5 and 16.0.17.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Privilege Context Switching Error
The product does not properly manage privileges while it is switching between different contexts that have different privileges or spheres of control.
How developers prevent this class of flaw
- Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
- Run your code using the lowest privileges that are required to accomplish the necessary tasks. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
- Consider following the principle of separation of privilege. Require multiple conditions to be met before permitting access to a system resource.
More Privilege Context Switching Error vulnerabilities (CWE-270)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other vulnerabilities in api
- 8.8 High severity
Recent Privilege Context Switching Error vulnerabilities
- 8.1 High severity
- 7.9 High severity
- 8.4 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
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