Asterisk Security Team
2011-Apr-21 21:40 UTC
[asterisk-users] AST-2011-006: Asterisk Manager User Shell Access
Asterisk Project Security Advisory - AST-2011-006
Product Asterisk
Summary Asterisk Manager User Shell Access
Nature of Advisory Permission Escalation
Susceptibility Remote Authenticated Sessions
Severity Minor
Exploits Known Yes
Reported On February 10, 2011
Reported By Mark Murawski <markm AT intellasoft DOT net>
Posted On April 21, 2011
Last Updated On April 21, 2011
Advisory Contact Matthew Nicholson <mnicholson at digium.com>
CVE Name
Description It is possible for a user of the Asterisk Manager Interface to
bypass a security check and execute shell commands when they
should not have that ability. Sending the "Async"
header with
the "Application" header during an Originate action,
allows
authenticated manager users to execute shell commands. Only
users with the "system" privilege should be able to do
this.
Resolution Asterisk now performs the proper access check where appropriate
during the originate manager action.
Affected Versions
Product Release Series
Asterisk Open Source 1.4.x All versions
Asterisk Open Source 1.6.1.x All versions
Asterisk Open Source 1.6.2.x All versions
Asterisk Open Source 1.8.x All versions
Asterisk Business Edition C.x.x All versions
Corrected In
Product Release
Asterisk Open Source 1.4.40.1, 1.6.1.25, 1.6.2.17.3, 1.8.3.3
Asterisk Business Edition C.3.6.4
Patches
URL Branch
http://downloads.asterisk.org/pub/security/AST-2011-006-1.4.diff 1.4
http://downloads.asterisk.org/pub/security/AST-2011-006-1.6.1.diff 1.6.1
http://downloads.asterisk.org/pub/security/AST-2011-006-1.6.2.diff 1.6.2
http://downloads.asterisk.org/pub/security/AST-2011-006-1.8.diff 1.8
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This document may be superseded by later versions; if so, the latest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/AST-2011-006.pdf and
http://downloads.digium.com/pub/security/AST-2011-006.html
Revision History
Date Editor Revisions Made
4/21/11 Matthew Nicholson Initial version
Asterisk Project Security Advisory - AST-2011-006
Copyright (c) 2011 Digium, Inc. All Rights Reserved.
Permission is hereby granted to distribute and publish this advisory in its
original, unaltered form.
Tzafrir Cohen
2011-Apr-22 20:45 UTC
[asterisk-users] AST-2011-006: Asterisk Manager User Shell Access
On Thu, Apr 21, 2011 at 04:40:39PM -0500, Asterisk Security Team wrote:> Asterisk Project Security Advisory - AST-2011-006 > > Product Asterisk > Summary Asterisk Manager User Shell Access > Nature of Advisory Permission Escalation > Susceptibility Remote Authenticated Sessions > Severity Minor > Exploits Known Yes > Reported On February 10, 2011 > Reported By Mark Murawski <markm AT intellasoft DOT net> > Posted On April 21, 2011 > Last Updated On April 21, 2011 > Advisory Contact Matthew Nicholson <mnicholson at digium.com> > CVE Name > > Description It is possible for a user of the Asterisk Manager Interface to > bypass a security check and execute shell commands when they > should not have that ability. Sending the "Async" header with > the "Application" header during an Originate action, allows > authenticated manager users to execute shell commands. Only > users with the "system" privilege should be able to do this. > > Resolution Asterisk now performs the proper access check where appropriate > during the originate manager action.So basically doing some dangerous stuff is only allowed for users with the 'system' write permissions. Which brings up the interesting question: are there any such users without such write permission? IIRC most of the sample I saw included it even before it was actually meaningful. In fact they all had something of the likes of: read = system,call,log,verbose,agent,user,config,dtmf,reporting,cdr,dialplan write = system,call,agent,user,config,command,reporting,originate So here's a mini poll: Do you have a manager interface user that does not have all the read and write permissions? If so: how have you managed to do so? * Reading documentation / source * An existing sample * Trial and Error -- Tzafrir Cohen icq#16849755 jabber:tzafrir.cohen at xorcom.com +972-50-7952406 mailto:tzafrir.cohen at xorcom.com http://www.xorcom.com iax:guest at local.xorcom.com/tzafrir