The Asterisk Development Team would like to announce security releases for
Asterisk 16, 17 and 18, and Certified Asterisk 16.8. The available releases are
released as versions 16.16.2, 17.9.3, 18.2.2 and 16.8-cert7.
These releases are available for immediate download at
The following security vulnerabilities were resolved in these versions:
- AST-2021-006: Crash when negotiating T.38 with a zero port
When Asterisk sends a re-invite initiating T.38 faxing and the endpoint
responds with a m=image line and zero port, a crash will occur in Asterisk.
This is a reoccurrence of AST-2019-004.
For a full list of changes in the current releases, please see the ChangeLogs:
The security advisory is available at:
Thank you for your continued support of Asterisk!