CVE-2021-26717

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.

• http://packetstormsecurity.com/files/161471/Asterisk-Project-Security-Advisory-AST-2021-002.htmlThird Party Advisory
• http://seclists.org/fulldisclosure/2021/Feb/58Mailing List, Patch, Third Party Advisory
• https://downloads.asterisk.org/pub/security/Vendor Advisory
• https://downloads.asterisk.org/pub/security/AST-2021-002.htmlVendor Advisory
• https://issues.asterisk.org/jira/browse/ASTERISK-29203Issue Tracking, Patch, Vendor Advisory
• http://packetstormsecurity.com/files/161471/Asterisk-Project-Security-Advisory-AST-2021-002.htmlThird Party Advisory
• http://seclists.org/fulldisclosure/2021/Feb/58Mailing List, Patch, Third Party Advisory
• https://downloads.asterisk.org/pub/security/Vendor Advisory
• https://downloads.asterisk.org/pub/security/AST-2021-002.htmlVendor Advisory
• https://issues.asterisk.org/jira/browse/ASTERISK-29203Issue Tracking, Patch, Vendor Advisory

Published

Feb 18, 2021

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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