Asterisk 13.37.1, 16.14.1, 17.8.1, 18.0.1 and 16.8-cert5 Now Available (Security)

The Asterisk Development Team would like to announce security releases for Asterisk 13, 16, 17 and 18, and Certified Asterisk 16.8. The available releases are released as versions 13.37.1, 16.14.1, 17.8.1, 18.0.1 and 16.8-cert5.

These releases are available for immediate download at

The following security vulnerabilities were resolved in these versions:

  • AST-2020-001: Remote crash in res_pjsip_session
    Upon receiving a new SIP Invite, Asterisk did not return the created dialog locked or referenced.

  • AST-2020-002: Outbound INVITE loop on challenge with different nonce. If Asterisk is challenged on an outbound INVITE and the nonce is changed in each response, Asterisk will continually send INVITEs in a loop. This causes Asterisk to consume more and more memory since the transaction will never terminate (even if the call is hung up), ultimately leading to a restart or shutdown of Asterisk. Outbound authentication must be configured on the endpoint for this to occur.

For a full list of changes in the current releases, please see the ChangeLogs:


The security advisories are available at:


Thank you for your continued support of Asterisk!