Hash: SHA256

             AUSCERT External Security Bulletin Redistribution

             Asterisk Project Security Advisory - AST-2018-009
                             21 September 2018


        AusCERT Security Bulletin Summary

Product:           Asterisk
Publisher:         Asterisk
Operating System:  Windows
                   UNIX variants (UNIX, Linux, OSX)
Impact/Access:     Denial of Service -- Remote/Unauthenticated
Resolution:        Patch/Upgrade
CVE Names:         CVE-2018-17281  

Original Bulletin: 

- --------------------------BEGIN INCLUDED TEXT--------------------

               Asterisk Project Security Advisory - AST-2018-009

       Product         Asterisk

       Summary         Remote crash vulnerability in HTTP websocket upgrade

 Nature of Advisory    Denial Of Service

   Susceptibility      Remote Unauthenticated Sessions

      Severity         Moderate

   Exploits Known      No

     Reported On       August 16, 2018

     Reported By       Sean Bright

      Posted On

   Last Updated On     September 20, 2018

  Advisory Contact     Rmudgett AT digium DOT com

      CVE Name         CVE-2018-17281

     Description       There is a stack overflow vulnerability in the res_http_websocket.so module of
                       Asterisk that allows an attacker to crash Asterisk via a specially crafted HTTP
                       request to upgrade the connection to a websocket. The attacker's request causes
                       Asterisk to run out of stack space and crash.

     Resolution        Disable HTTP websocket access by not loading the res_http_websocket.so module
                       or upgrade Asterisk to a fixed version.

                               Affected Versions

              Product                  Release

       Asterisk Open Source             13.x      All releases

       Asterisk Open Source             14.x      All releases

       Asterisk Open Source             15.x      All releases

        Certified Asterisk              13.21     All releases

                                 Corrected In

                     Product                                             Release

               Asterisk Open Source                              13.23.1, 14.7.8, 15.6.1

                Certified Asterisk                                     13.21-cert3


                     SVN URL                                             Revision

http://downloads.asterisk.org/pub/security/         Asterisk 13

http://downloads.asterisk.org/pub/security/         Asterisk 14

http://downloads.asterisk.org/pub/security/         Asterisk 15

http://downloads.asterisk.org/pub/security/         Certified Asterisk 13.21

        Links          https://issues.asterisk.org/jira/browse/ASTERISK-28013

Asterisk Project Security Advisories are posted at http://www.asterisk.org/

This document may be superseded by later versions; if so, the latest version
will be posted at http://downloads.digium.com/pub/security/AST-2018-009.pdf and

                               Revision History

       Date                   Editor                                Revisions Made

August 31, 2018      Richard Mudgett            Initial revision

September 20, 2018   Richard Mudgett            Added CVE name.

               Asterisk Project Security Advisory - AST-2018-009
              Copyright (C) 2018 Digium, Inc. All Rights Reserved.
  Permission is hereby granted to distribute and publish this advisory in its
                           original, unaltered form.

- --------------------------END INCLUDED TEXT--------------------

You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.

NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members.  As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.

NOTE: This is only the original release of the security bulletin.  It may
not be updated when updates to the original are made.  If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.

Contact information for the authors of the original document is included
in the Security Bulletin above.  If you have any questions or need further
information, please contact them directly.

Previous advisories and external security bulletins can be retrieved from:


Australian Computer Emergency Response Team
The University of Queensland
Qld 4072

Internet Email: auscert@auscert.org.au
Facsimile:      (07) 3365 7031
Telephone:      (07) 3365 4417 (International: +61 7 3365 4417)
                AusCERT personnel answer during Queensland business hours
                which are GMT+10:00 (AEST).
                On call after hours for member emergencies only.
Comment: http://www.auscert.org.au/render.html?it=1967