CVEs-PoC/2021/CVE-2021-26717.md

### [CVE-2021-26717](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-26717)
![](https://img.shields.io/static/v1?label=Product&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Vulnerability&message=n%2Fa&color=brighgreen)

### Description

An issue was discovered in Sangoma Asterisk 16.x before 16.16.1, 17.x before 17.9.2, and 18.x before 18.2.1 and Certified Asterisk before 16.8-cert6. When re-negotiating for T.38, if the initial remote response was delayed just enough, Asterisk would send both audio and T.38 in the SDP. If this happened, and the remote responded with a declined T.38 stream, then Asterisk would crash.

### POC

#### Reference
- http://packetstormsecurity.com/files/161471/Asterisk-Project-Security-Advisory-AST-2021-002.html

#### Github
No PoCs found on GitHub currently.