Product

Asterisk

Summary

An unsuspecting user could crash Asterisk with multiple hold/unhold requests

Nature of Advisory

Denial of Service

Susceptibility

Remote authenticated sessions

Severity

Moderate

Exploits Known

No

Reported On

December 9, 2020

Reported By

Edvin Vidmar

Posted On

Last Updated On

February 19, 2021

Advisory Contact

gjoseph AT sangoma DOT com

CVE Name

CVE-2021-26713

Description

Due to a signedness comparison mismatch, an authenticated WebRTC client could cause a stack overflow and Asterisk crash by sending multiple hold/unhold requests in quick succession.

Modules Affected

res_rtp_asterisk.c

Resolution

The packet size comparison terms have been corrected.

Affected Versions

Product

Release Series

Asterisk Open Source

16.x

16.16.0

Asterisk Open Source

17.x

17.9.1

Asterisk Open Source

18.x

18.2.0

Certified Asterisk

16.x

16.8-cert5

Corrected In

Product

Release

Asterisk Open Source

16.16.1, 17.9.2, 18.2.1

Certified Asterisk

16.8-cert6

Patches

Patch URL

Revision

https:/downloads.asterisk.org/pub/security/AST-2021-004-16.diff

16.6.1

https:/downloads.asterisk.org/pub/security/AST-2021-004-17.diff

17.9.2

https:/downloads.asterisk.org/pub/security/AST-2021-004-18.diff

18.2.1

https:/downloads.asterisk.org/pub/security/AST-2021-004-16.8.diff

Certified Asterisk 16.8-cert6

Links

https://issues.asterisk.org/jira/browse/ASTERISK-29205

https://downloads.asterisk.org/pub/security/AST-2021-004.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This document may be superseded by later versions; if so, the latest version will be posted at https://downloads.digium.com/pub/security/AST-2021-004.pdf and https://downloads.digium.com/pub/security/AST-2021-004.html

Revision History

Date

Editor

Revisions Made

February 4, 2021

George Joseph

Initial revision

February 9, 2021

George Joseph

Added CVE