Go to homepageCyberStrike

Menu

Star on GitHub · 3.2k
Sign inDownload

CVE-2021-26717

7.5 · HIGH

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.

Published Feb 18, 2021EPSS 2.20%

Overview

CVE-2021-26717 is a high-severity vulnerability. It was published on February 18, 2021 and has a CVSS 3.1 base score of 7.5 (HIGH).

This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.

Technical 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.

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References

Refpacketstormsecurity.com/files/161471/Asterisk-Project-Security-Advisory-AST-2021-002.htmlRefseclists.org/fulldisclosure/2021/Feb/58Refdownloads.asterisk.org/pub/security/Refdownloads.asterisk.org/pub/security/AST-2021-002.htmlRefissues.asterisk.org/jira/browse/ASTERISK-29203Refpacketstormsecurity.com/files/161471/Asterisk-Project-Security-Advisory-AST-2021-002.htmlRefseclists.org/fulldisclosure/2021/Feb/58Refdownloads.asterisk.org/pub/security/Refdownloads.asterisk.org/pub/security/AST-2021-002.htmlRefissues.asterisk.org/jira/browse/ASTERISK-29203

How CyberStrike helps

Frequently asked questions

What is CVE-2021-26717?

CVE-2021-26717 is a high-severity vulnerability. It was published on February 18, 2021 and has a CVSS 3.1 base score of 7.5 (HIGH).

How severe is CVE-2021-26717?

This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.

How do I fix or remediate CVE-2021-26717?

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2021-26717?

CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2021-26717 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.

Related HIGH CVEs from 2021

View all
Browse by year2026202520242023202220212020201920182017201620152014201320122011201020092008200720062005200420032002200120001999