[asterisk-announce] ASA-2007-013: IAX2 users can cause unauthorized
data disclosure
Kevin P. Fleming
kpfleming at digium.com
Fri May 4 09:20:02 MST 2007
> Asterisk Project Security Advisory - ASA-2007-013
>
> +----------------------------------------------------------------------------------+
> | Product | Asterisk |
> |----------------------+-----------------------------------------------------------|
> | Summary | IAX2 users can cause unauthorized data disclosure |
> |----------------------+-----------------------------------------------------------|
> | Nature of Advisory | Unauthorized information disclosure |
> |----------------------+-----------------------------------------------------------|
> | Susceptibility | Remote authenticated sessions |
> |----------------------+-----------------------------------------------------------|
> | Severity | Low |
> |----------------------+-----------------------------------------------------------|
> | Exploits Known | No |
> |----------------------+-----------------------------------------------------------|
> | Reported On | April 27, 2007 |
> |----------------------+-----------------------------------------------------------|
> | Reported By | Tim Panton, Mexuar, <tim at mexuar.com> |
> | | |
> | | Birgit Arkesteijn, Westhawk, <birgit at westhawk.co.uk> |
> |----------------------+-----------------------------------------------------------|
> | Posted On | May 4, 2007 |
> |----------------------+-----------------------------------------------------------|
> | Last Updated On | May 4, 2007 |
> |----------------------+-----------------------------------------------------------|
> | Advisory Contact | kpfleming at digium.com |
> |----------------------+-----------------------------------------------------------|
> | CVE Name | CVE-2007-2488 |
> +----------------------------------------------------------------------------------+
>
> +----------------------------------------------------------------------------------+
> | Description | > From: Tim Panton <tim at mexuar.com> |
> | | |
> | | > Date: 27 April 2007 08:02:36 BDT |
> | | |
> | | > To: "Kevin P. Fleming" <kpfleming at digium.com> |
> | | |
> | | > Subject: Possible IAX2 vulnerability (Minor) |
> | | |
> | | > |
> | | |
> | | > We've stumbled on a bug in the way Asterisk's IAX2 handles text |
> | | |
> | | > frames. |
> | | |
> | | > I'm emailing you because it is a borderline security |
> | | vulnerability, |
> | | |
> | | > and my |
> | | |
> | | > friends in the security world tell me that I should notify the |
> | | |
> | | > vendor privately |
> | | |
> | | > first. If you feel it isn't a security issue, let me know and |
> | | I'll |
> | | |
> | | > put it in mantis. |
> | | |
> | | > |
> | | |
> | | > chan_iax2 assumes that the content of a text frame is a null |
> | | |
> | | > terminated |
> | | |
> | | > string (C style), and when time comes to forward the string it |
> | | uses |
> | | |
> | | > strlen |
> | | |
> | | > to determine the message length. |
> | | |
> | | > |
> | | |
> | | > If you send a frame without a 0 byte in it, Asterisk forwards a |
> | | |
> | | > frame that |
> | | |
> | | > includes the sent data and some extra (presumably heap) data. |
> | | |
> | | > |
> | | |
> | | > If an attacker were lucky, the extra data could contain |
> | | something |
> | | |
> | | > interesting. |
> | | |
> | | > Or conceivably it could cause a segmentation violation. |
> +----------------------------------------------------------------------------------+
>
> +----------------------------------------------------------------------------------+
> | Resolution | Asterisk code has been modified to enforce null-termination of |
> | | incoming text frames received by the IAX2 channel driver |
> | | (chan_iax2). When text frames are received without |
> | | null-termination, this may result in the last byte of data in the |
> | | frame being lost, if the IAX2 reception process does not have space |
> | | in its receive buffer to add a null character. |
> | | |
> | | As this vulnerability is of 'low' severity, it does not justify new |
> | | releases of Asterisk solely for mitigating its impact. The fix for |
> | | this vulnerability has been committed to the Asterisk Subversion |
> | | source code repositories and is available to all users who wish to |
> | | upgrade to a prerelease checkout of the respective development |
> | | branch for their release series of Asterisk. All other users can |
> | | upgrade when the next regularly scheduled release of their product |
> | | is produced. |
> +----------------------------------------------------------------------------------+
>
> +----------------------------------------------------------------------------------+
> | Affected Versions |
> |----------------------------------------------------------------------------------|
> | Product | Release | |
> | | Series | |
> |----------------------------------+-------------+---------------------------------|
> | Asterisk Open Source | 1.0.x | has not been evaluated as this |
> | | | release series is no longer |
> | | | maintained |
> |----------------------------------+-------------+---------------------------------|
> | Asterisk Open Source | 1.2.x | all releases prior to 1.2.19 |
> |----------------------------------+-------------+---------------------------------|
> | Asterisk Open Source | 1.4.x | all releases prior to 1.4.4 |
> |----------------------------------+-------------+---------------------------------|
> | Asterisk Business Edition | A.x.x | all releases |
> |----------------------------------+-------------+---------------------------------|
> | Asterisk Business Edition | B.x.x | all releases prior to B.2.1 |
> |----------------------------------+-------------+---------------------------------|
> | AsteriskNOW | pre-release | all releases prior to and |
> | | | including Beta 5 |
> |----------------------------------+-------------+---------------------------------|
> | Asterisk Appliance Developer Kit | 0.x.x | all releases prior to 0.4.1 |
> +----------------------------------------------------------------------------------+
>
> +----------------------------------------------------------------------------------+
> | Corrected In |
> |----------------------------------------------------------------------------------|
> | Product | Release |
> |----------------------+-----------------------------------------------------------|
> | Asterisk Open Source | 1.2.19 and 1.4.4 will be available from |
> | | ftp://ftp.digium.com/pub/telephony/asterisk when released |
> |----------------------+-----------------------------------------------------------|
> | Asterisk Business | B.2.1, will be available from the Asterisk Business |
> | Edition | Edition user portal on http://www.digium.com or via |
> | | Digium Technical Support when released |
> |----------------------+-----------------------------------------------------------|
> | AsteriskNOW | Beta 6, when available from http://www.asterisknow.org, |
> | | Beta 5 users can use 'System Update' in the appliance |
> | | control panel to update their version of AsteriskNOW when |
> | | Asterisk 1.4.4 has been released |
> |----------------------+-----------------------------------------------------------|
> | Asterisk Appliance | 0.4.1, will be available from |
> | Developer Kit | ftp://ftp.digium.com/pub/telephony/aadk when released |
> +----------------------------------------------------------------------------------+
>
> +----------------------------------------------------------------------------------+
> | Links | http://bugs.digium.com/view.php?id=9638 |
> +----------------------------------------------------------------------------------+
>
> +----------------------------------------------------------------------------------+
> | 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://ftp.digium.com/pub/asa/ASA-2007-013.pdf. |
> +----------------------------------------------------------------------------------+
>
> +----------------------------------------------------------------------------------+
> | Revision History |
> |----------------------------------------------------------------------------------|
> | Date | Editor | Revisions Made |
> |-------------------+-----------------------------+--------------------------------|
> | May 4, 2007 | kpfleming at digium.com | initial release |
> +----------------------------------------------------------------------------------+
>
> Asterisk Project Security Advisory - ASA-2007-013
> Copyright (c) 2007 Digium, Inc. All Rights Reserved.
> Permission is hereby granted to distribute and publish this advisory in its original,
> unaltered form.
More information about the asterisk-announce
mailing list