Freepbx: Improper Access Control
CVE-2023-43336 is a high-severity improper access control vulnerability in Freepbx from Sangoma, with a CVSS 3.1 base score of 8.8 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. The record lists versions 15.0.16, 16.0.17, 15.0.18 as the first without the flaw, so updating Freepbx to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.87% chance of exploitation within 30 days, higher than 59% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Freepbx to 15.0.16 or 16.0.17 or 15.0.18 or 16.0.40, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Sangoma | Freepbx | before 15.0.16; 16.0.2 up to, but not including, 16.0.17; before 15.0.18; 16.0.2 up to, but not including, 16.0.40 | 15.0.16, 16.0.17, 15.0.18, 16.0.40 |
Version data comes from NVD's product matching. 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
- 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:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
Official description
Sangoma Technologies FreePBX before cdr 15.0.18, 16.0.40, 15.0.16, and 16.0.17 was discovered to contain an access control issue via a modified parameter value, e.g., changing extension=self to extension=101.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Access Control
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
How developers prevent this class of flaw
- Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
- Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Technical write-ups (may include proof of concept)
Other references
Other vulnerabilities in Freepbx
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 7.2 High severity
Recent Improper Access Control vulnerabilities
- 7.1 High severity
- 7.1 High severity
- 9.8 Critical severity
- 9.1 Critical severity
- 8.1 High severity
- 7.5 High severity
Spotted an error? Tell us.