Asterisk 13.21-cert4, 13.27.1, 15.7.3, 16.4.1 Now Available (Security Release)

The Asterisk Development Team would like to announce security releases for
Asterisk 13, 15 and 16, and Certified Asterisk 13.21. The available releases are
released as versions 13.27.1, 15.7.3, 16.4.1 and 13.21-cert4.

These releases are available for immediate download at

The following security vulnerabilities were resolved in these versions:

    • AST-2019-002: Remote crash vulnerability with MESSAGE messages
      A specially crafted SIP in-dialog MESSAGE message can cause Asterisk to crash.
  • AST-2019-003: Remote Crash Vulnerability in chan_sip channel driver
    When T.38 faxing is done in Asterisk a T.38 reinvite may be sent to an
    endpoint to switch it to T.38. If the endpoint responds with an improperly
    formatted SDP answer including both a T.38 UDPTL stream and an audio or video
    stream containing only codecs not allowed on the SIP peer or user a crash will
    occur. The code incorrectly assumes that there will be at least one common
    codec when T.38 is also in the SDP answer.

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!

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