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.
https://medium.com/%40janirudransh/security-disclosure-of-vulnerability-cve-2023-23336-4429d416f826