CVE-2021-45461

Name: CVE-2021-45461
Creator: NVD / NIST
Published: 2021-12-22T19:15:11.807+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 21.66%

Last modified Jun 17, 2026

CVE-2021-45461 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. FreePBX, when restapps (aka Rest Phone Apps) 15.0.19.87, 15.0.19.88, 16.0.18.40, or 16.0.18.41 is installed, allows remote attackers to execute arbitrary code, as exploited in the wild in December 2021. The fixed versions are 15.0.20 and 16.0.19.. EPSS estimates a 21.66% chance of exploitation in the next 30 days.

Description

FreePBX, when restapps (aka Rest Phone Apps) 15.0.19.87, 15.0.19.88, 16.0.18.40, or 16.0.18.41 is installed, allows remote attackers to execute arbitrary code, as exploited in the wild in December 2021. The fixed versions are 15.0.20 and 16.0.19.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

21.66%

97.3th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Sangoma	Restapps	15.0.19.87
Sangoma	Restapps	15.0.19.88
Sangoma	Restapps	16.0.18.40
Sangoma	Restapps	16.0.18.41

References

https://community.freepbx.org/t/0-day-freepbx-exploit/80092Exploit, Issue Tracking, Vendor Advisory
https://community.freepbx.org/t/security-issue-potential-rest-phone-apps-rce/80109Vendor Advisory
https://wiki.freepbx.org/display/FOP/2021-12-21+SECURITY%3A+Potential+Rest+Phone+Apps+RCEVendor Advisory
https://community.freepbx.org/t/0-day-freepbx-exploit/80092Exploit, Issue Tracking, Vendor Advisory
https://community.freepbx.org/t/security-issue-potential-rest-phone-apps-rce/80109Vendor Advisory
https://wiki.freepbx.org/display/FOP/2021-12-21+SECURITY%3A+Potential+Rest+Phone+Apps+RCEVendor Advisory

Timeline

Published: Dec 22, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-45461?

How severe is CVE-2021-45461?

CVE-2021-45461 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 21.66% probability of exploitation in the next 30 days.

How do I fix CVE-2021-45461?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-45461?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST