Asterisk 13.1-cert5 and 13.8.1 Now Available (Security Release)

The Asterisk Development Team has announced security releases for Certified Asterisk 13.1 and Asterisk 13. The available security releases are released as versions 13.1-cert5, and 13.8.1. These releases are available for immediate download http://downloads.asterisk.org/pub/telephony/asterisk/releases

The release of these versions resolves the following security vulnerabilities:

  • AST-2016-004: Long contact URIs in REGISTER requests can crash Asterisk

Asterisk may crash when processing an incoming REGISTER request if that REGISTER contains a Contact header with a lengthy URI. This crash will only happen for requests that pass authentication. Unauthenticated REGISTER requests will not result in a crash occurring.

  • AST-2016-005: TCP denial of service in PJProject

PJProject has a limit on the number of TCP connections that it can accept. Furthermore, PJProject does not close TCP connections it accepts. By default, this value is approximately 60. An attacker can deplete the number of allowed TCP connections by opening TCP connections and sending no data to Asterisk.

If PJProject has been compiled in debug mode, then once the number of allowed TCP connections has been depleted, the next attempted TCP connection to Asterisk will crash due to an assertion in PJProject. If PJProject has not been compiled in debug mode, then any further TCP connection attempts will be rejected. This makes Asterisk unable to process TCP SIP traffic.

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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