Asterisk Project Security Advisory – AST-2021-008

Asterisk Project Security Advisory – AST-2021-008

Product Asterisk
Summary Remote crash when using IAX2 channel driver
Nature of Advisory Denial of service
Susceptibility Remote unauthenticated sessions
Severity Major
Exploits Known No
Reported On April 13, 2021
Reported By Michael Welk
Posted On
Last Updated On July 6, 2021
Advisory Contact kharwell AT sangoma DOT com
CVE Name CVE-2021-32558

Description If the IAX2 channel driver receives a packet that
contains an unsupported media format it can cause a
crash to occur in Asterisk.
Modules Affected chan_iax2.c

Resolution Checks are now in place that make it so packets containing
unsupported media formats are ignored/dropped in the IAX2
channel driver. This ensures Asterisk no longer crashes.

Affected Versions
Product Release Series
Asterisk Open Source 13.x All versions
Asterisk Open Source 16.x All versions
Asterisk Open Source 17.x All versions
Asterisk Open Source 18.x All versions
Certified Asterisk 16.8 All versions

Corrected In
Product Release
Asterisk Open Source 13.38.3, 16.19.1, 17.9.4, 18.5.1
Certified Asterisk 16.8-cert10

Patches
Patch URL Revision
http://downloads.digium.com/pub/security/AST-2021-008-13.diff Asterisk
13
http://downloads.digium.com/pub/security/AST-2021-008-16.diff Asterisk
16
http://downloads.digium.com/pub/security/AST-2021-008-17.diff Asterisk
17
http://downloads.digium.com/pub/security/AST-2021-008-18.diff Asterisk
18
http://downloads.digium.com/pub/security/AST-2021-008-16.8.diff Certified
Asterisk
16.8

Links https://issues.asterisk.org/jira/browse/ASTERISK-29392

https://downloads.asterisk.org/pub/security/AST-2021-008.html

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

This document may be superseded by later versions; if so, the latest
version will be posted at
http://downloads.digium.com/pub/security/AST-2021-008.pdf and
http://downloads.digium.com/pub/security/AST-2021-008.html

Revision History
Date Editor Revisions Made
May 10, 2021 Kevin Harwell Initial revision

Asterisk Project Security Advisory – AST-2021-008
Copyright © 2021 Digium, Inc. All Rights Reserved.
Permission is hereby granted to distribute and publish this advisory in its
original, unaltered form.