==================================================================== CERT-Renater Note d'Information No. 2012/VULN342 ____________________________________________________________________ DATE : 05/09/2012 HARDWARE PLATFORM(S): / OPERATING SYSTEM(S) : Systems running Asterisk Open Source versions 1.8.x, 10.x, Certified Asterisk version 1.8.11, Asterisk Digiumphones version 10.x.x-digiumphones, Asterisk Business Edition version C.3.x. ====================================================================== http://downloads.digium.com/pub/security/AST-2012-012.html http://downloads.digium.com/pub/security/AST-2012-013.html ______________________________________________________________________ Asterisk Project Security Advisory - AST-2012-012 Product Asterisk Summary Asterisk Manager User Unauthorized Shell Access Nature of Advisory Permission Escalation Susceptibility Remote Authenticated Sessions Severity Minor Exploits Known No Reported On July 13, 2012 Reported By Zubair Ashraf of IBM X-Force Research Posted On August 30, 2012 Last Updated On August 30, 2012 Advisory Contact Matt Jordan < mjordan AT digium DOT com > CVE Name CVE-2012-2186 Description The AMI Originate action can allow a remote user to specify information that can be used to execute shell commands on the system hosting Asterisk. This can result in an unwanted escalation of permissions, as the Originate action, which requires the "originate" class authorization, can be used to perform actions that would typically require the "system" class authorization. Previous attempts to prevent this permission escalation (AST-2011-006, AST-2012-004) have sought to do so by inspecting the names of applications and functions passed in with the Originate action and, if those applications/functions matched a predefined set of values, rejecting the command if the user lacked the "system" class authorization. As reported by IBM X-Force Research, the "ExternalIVR" application is not listed in the predefined set of values. The solution for this particular vulnerability is to include the "ExternalIVR" application in the set of defined applications/functions that require "system" class authorization. Unfortunately, the approach of inspecting fields in the Originate action against known applications/functions has a significant flaw. The predefined set of values can be bypassed by creative use of the Originate action or by certain dialplan configurations, which is beyond the ability of Asterisk to analyze at run-time. Attempting to work around these scenarios would result in severely restricting the applications or functions and prevent their usage for legitimate means. As such, any additional security vulnerabilities, where an application/function that would normally require the "system" class authorization can be executed by users with the "originate" class authorization, will not be addressed. Instead, the README-SERIOUSLY.bestpractices.txt file has been updated to reflect that the AMI Originate action can result in commands requiring the "system" class authorization to be executed. Proper system configuration can limit the impact of such scenarios. The next release of each version of Asterisk will contain, in addition to the fix for the "ExternalIVR" application, an updated README-SERIOUSLY.bestpractices.txt file. Resolution Asterisk now checks for the "ExternalIVR" application when processing the Originate action. Additionally, the README-SERIOUSLY.bestpractices.txt file has been updated. It is highly recommended that, if AMI is utilized with accounts that have the "originate" class authorization, Asterisk is run under a defined user that does not have root permissions. Accounts with the "originate" class authorization should be treated in a similar manner to those with the "system" class authorization. Affected Versions Product Release Series Asterisk Open Source 1.8.x All versions Asterisk Open Source 10.x All versions Certified Asterisk 1.8.11 All versions Asterisk Digiumphones 10.x.x-digiumphones All versions Asterisk Business Edition C.3.x All versions Corrected In Product Release Asterisk Open Source 1.8.15.1, 10.7.1 Certified Asterisk 1.8.11-cert6 Asterisk Digiumphones 10.7.1-digiumphones Asterisk Business Edition C.3.7.6 Patches SVN URL Revisionhttp://downloads.asterisk.org/pub/security/AST-2012-012-1.8.diff Asterisk 1.8 http:downloads.asterisk.org/pub/security/AST-2012-012-10.diff Asterisk 10 Links https://issues.asterisk.org/jira/browse/ASTERISK-20132 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-2012-012.pdf and http://downloads.digium.com/pub/security/AST-2012-012.html Revision History Date Editor Revisions Made 08/27/2012 Matt Jordan Initial version Asterisk Project Security Advisory - AST-2012-012 Copyright (c) 2012 Digium, Inc. All Rights Reserved. Permission is hereby granted to distribute and publish this advisory in its original, unaltered form. -------------------------------------------------------------------------- Asterisk Project Security Advisory - AST-2012-013 Product Asterisk Summary ACL rules ignored when placing outbound calls by certain IAX2 users Nature of Advisory Unauthorized use of system Susceptibility Remote Authenticated Sessions Severity Moderate Exploits Known None Reported On 07/27/2012 Reported By Alan Frisch Posted On 08/30/2012 Last Updated On August 30, 2012 Advisory Contact Matt Jordan < mjordan AT digium DOT com > CVE Name CVE-2012-4737 Description When an IAX2 call is made using the credentials of a peer defined in a dynamic Asterisk Realtime Architecture (ARA) backend, the ACL rules for that peer are not applied to the call attempt. This allows for a remote attacker who is aware of a peer's credentials to bypass the ACL rules set for that peer. Resolution The ACL rules for peers defined in an ARA backend are now honored. Users of chan_iax2 should upgrade to the corrected versions; apply a provided patch; or define their IAX2 peers outside of an ARA backend in a static configuration file. Affected Versions Product Release Series Asterisk Open Source 1.8.x All versions Asterisk Open Source 10.x All versions Certified Asterisk 1.8.11 All versions Asterisk Digiumphones 10.x.x-digiumphones All versions Asterisk Business Edition C.3.x All versions Corrected In Product Release Asterisk Open Source 1.8.15.1, 10.7.1 Certified Asterisk 1.8.11-cert7 Asterisk Digiumphones 10.7.1-digiumphones Asterisk Business Edition C.3.7.6 Patches SVN URL Revision http://downloads.asterisk.org/pub/security/AST-2012-013.1.8.diff Asterisk 1.8 http://downloads.asterisk.org/pub/security/AST-2012-013.10.diff Asterisk 10 Links https://issues.asterisk.org/jira/browse/ASTERISK-20186 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-2012-013.pdf and http://downloads.digium.com/pub/security/AST-2012-013.html Revision History Date Editor Revisions Made 08/27/2012 Matt Jordan Initial Revision Asterisk Project Security Advisory - AST-2012-013 Copyright (c) 2012 Digium, Inc. All Rights Reserved. Permission is hereby granted to distribute and publish this advisory in its original, unaltered form. ====================================================================== ========================================================= Serveur de référence du CERT-Renater https://services.renater.fr/ssi/ ========================================================= + CERT-RENATER | tel : 01-53-94-20-44 + + 23 - 25 Rue Daviel | fax : 01-53-94-20-41 + + 75013 Paris | email: certsvp@renater.fr + =========================================================