What can we help you find?

Asterisk 13.19.2, 14.7.6, 15.2.2 and 13.18-cert3 Now Available (Security)

The Asterisk Development Team would like to announce security releases for
Asterisk 13, 14 and 15, and Certified Asterisk 13.18. The available releases are
released as versions 13.19.2, 14.7.6, 15.2.2 and 13.18-cert3.

These releases are available for immediate download at


The following security vulnerabilities were resolved in these versions:

  • AST-2018-001: Crash when receiving unnegotiated dynamic payload
    The RTP support in Asterisk maintains its own registry of dynamic codecs and
    desired payload numbers. While an SDP negotiation may result in a codec using
    a different payload number these desired ones are still stored internally.
    When an RTP packet was received this registry would be consulted if the
    payload number was not found in the negotiated SDP. This registry was
    incorrectly consulted for all packets, even those which are dynamic. If the
    payload number resulted in a codec of a different type than the RTP stream
    (for example the payload number resulted in a video codec but the stream
    carried audio) a crash could occur if no stream of that type had been
    negotiated. This was due to the code incorrectly assuming that a stream of the
    type would always exist.

  • AST-2018-002: Crash when given an invalid SDP media format description
    By crafting an SDP message with an invalid media format description Asterisk
    crashes when using the pjsip channel driver because pjproject's sdp parsing
    algorithm fails to catch the invalid media format description.

  • AST-2018-003: Crash with an invalid SDP fmtp attribute
    By crafting an SDP message body with an invalid fmtp attribute Asterisk
    crashes when using the pjsip channel driver because pjproject's fmtp retrieval
    function fails to check if fmtp value is empty (set empty if previously parsed
    as invalid).

  • AST-2018-004: Crash when receiving SUBSCRIBE request
    When processing a SUBSCRIBE request the res_pjsip_pubsub module stores the
    accepted formats present in the Accept headers of the request. This code did
    not limit the number of headers it processed despite having a fixed limit of
    32. If more than 32 Accept headers were present the code would write outside
    of its memory and cause a crash.

  • AST-2018-005: Crash when large numbers of TCP connections are closed suddenly
    A crash occurs when a number of authenticated INVITE messages are sent over
    TCP or TLS and then the connection is suddenly closed. This issue leads to a
    segmentation fault.

  • AST-2018-006: WebSocket frames with 0 sized payload causes DoS
    When reading a websocket, the length was not being checked. If a payload of
    length 0 was read, it would result in a busy loop that waited for the
    underlying connection to close.

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!