Asterisk Project Security Advisory - AST-2017-004

Product

Asterisk

Summary

Memory exhaustion on short SCCP packets

Nature of Advisory

Denial of Service

Susceptibility

Remote Unauthenticated Sessions

Severity

Critical

Exploits Known

No

Reported On

April 13, 2017

Reported By

Sandro Gauci

Posted On


Last Updated On

April 13, 2017

Advisory Contact

George Joseph <gjoseph AT digium DOT com>

CVE Name




Description

A remote memory exhaustion can be triggered by sending an SCCP packet to Asterisk system with “chan_skinny” enabled that is larger than the length of the SCCP header but smaller than the packet length specified in the header. The loop that reads the rest of the packet doesn’t detect that the call to read() returned end-of-file before the expected number of bytes and continues infinitely. The “partial data” message logging in that tight loop causes Asterisk to exhaust all available memory.


Resolution

If support for the SCCP protocol is not required, remove or disable the module.


If support for SCCP is required, an upgrade to Asterisk will be necessary.


Affected Versions

Product

Release Series


Asterisk Open Source

11.x

Unaffected

Asterisk Open Source

13.x

All versions

Asterisk Open Source

14.x

All versions

Certified Asterisk

13.13

All versions


Corrected In

Product

Release

Asterisk Open Source

13.15.1, 14.4.1

Certified Asterisk

13.13-cert4




Patches

SVN URL

Revision







Links



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This document may be superseded by later versions; if so, the latest version will be posted at http://downloads.digium.com/pub/security/.pdf and http://downloads.digium.com/pub/security/.html


Revision History

Date

Editor

Revisions Made

13 April 2017

George Joseph

Initial report created


Asterisk Project Security Advisory -
Copyright © 2017 Digium, Inc. All Rights Reserved.
Permission is hereby granted to distribute and publish this advisory in its original, unaltered form.