Date: 09 January 2009
References: ESB-2009.1641
Click here for printable version
Click here for PGP verifiable version
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
===========================================================================
AUSCERT External Security Bulletin Redistribution
ESB-2009.0026 -- [UNIX/Linux]
Asterisk - Information leak in IAX2 authentication
9 January 2009
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: Asterisk
Publisher: Asterisk
Operating System: UNIX variants (UNIX, Linux, OSX)
Impact: Reduced Security
Access: Remote/Unauthenticated
CVE Names: CVE-2009-0041
Original Bulletin:
http://downloads.digium.com/pub/security/AST-2009-001.html
- --------------------------BEGIN INCLUDED TEXT--------------------
Asterisk Project Security Advisory - AST-2009-001
+------------------------------------------------------------------------+
| Product | Asterisk |
|----------------------+-------------------------------------------------|
| Summary | Information leak in IAX2 authentication |
|----------------------+-------------------------------------------------|
| Nature of Advisory | Unauthorized data disclosure |
|----------------------+-------------------------------------------------|
| Susceptibility | Remote Unauthenticated Sessions |
|----------------------+-------------------------------------------------|
| Severity | Minor |
|----------------------+-------------------------------------------------|
| Exploits Known | Yes |
|----------------------+-------------------------------------------------|
| Reported On | October 15, 2008 |
|----------------------+-------------------------------------------------|
| Reported By | http://www.unprotectedhex.com |
|----------------------+-------------------------------------------------|
| Posted On | January 7, 2009 |
|----------------------+-------------------------------------------------|
| Last Updated On | January 7, 2009 |
|----------------------+-------------------------------------------------|
| Advisory Contact | Tilghman Lesher < tlesher AT digium DOT com > |
|----------------------+-------------------------------------------------|
| CVE Name | CVE-2009-0041 |
+------------------------------------------------------------------------+
+------------------------------------------------------------------------+
| Description | IAX2 provides a different response during authentication |
| | when a user does not exist, as compared to when the |
| | password is merely wrong. This allows an attacker to |
| | scan a host to find specific users on which to |
| | concentrate password cracking attempts. |
| | |
| | The workaround involves sending back responses that are |
| | valid for that particular site. For example, if it were |
| | known that a site only uses RSA authentication, then |
| | sending back an MD5 authentication request would |
| | similarly identify the user as not existing. The |
| | opposite is also true. So the solution is always to send |
| | back an authentication response that corresponds to a |
| | known frequency with which real authentication responses |
| | are returned, when the user does not exist. This makes |
| | it very difficult for an attacker to guess whether a |
| | user exists or not, based upon this particular |
| | mechanism. |
+------------------------------------------------------------------------+
+------------------------------------------------------------------------+
| Resolution | Upgrade to revision 167259 of the 1.2 branch or 167260 of |
| | the 1.4 branch or one of the releases noted below. |
+------------------------------------------------------------------------+
+------------------------------------------------------------------------+
| Affected Versions |
|------------------------------------------------------------------------|
| Product | Release | |
| | Series | |
|----------------------------+---------+---------------------------------|
| Asterisk Open Source | 1.2.x | All version prior to 1.2.31 |
|----------------------------+---------+---------------------------------|
| Asterisk Open Source | 1.4.x | All versions prior to |
| | | 1.4.23-rc4 |
|----------------------------+---------+---------------------------------|
| Asterisk Open Source | 1.6.x | All versions prior to |
| | | 1.6.0.3-rc2 |
|----------------------------+---------+---------------------------------|
| Asterisk Addons | 1.2.x | Not affected |
|----------------------------+---------+---------------------------------|
| Asterisk Addons | 1.4.x | Not affected |
|----------------------------+---------+---------------------------------|
| Asterisk Addons | 1.6.x | Not affected |
|----------------------------+---------+---------------------------------|
| Asterisk Business Edition | A.x.x | All versions |
|----------------------------+---------+---------------------------------|
| Asterisk Business Edition | B.x.x | All versions prior to B.2.5.7 |
|----------------------------+---------+---------------------------------|
| Asterisk Business Edition | C.1.x.x | All versions prior to C.1.10.4 |
|----------------------------+---------+---------------------------------|
| Asterisk Business Edition | C.2.x.x | All versions prior to C.2.1.2.1 |
|----------------------------+---------+---------------------------------|
| AsteriskNOW | 1.5 | Not affected |
|----------------------------+---------+---------------------------------|
| s800i (Asterisk Appliance) | 1.2.x | All versions prior to 1.3.0 |
+------------------------------------------------------------------------+
+------------------------------------------------------------------------+
| Corrected In |
|------------------------------------------------------------------------|
| Product | Release |
|--------------------------------------------+---------------------------|
| Asterisk Open Source | 1.2.31 |
|--------------------------------------------+---------------------------|
| Asterisk Open Source | 1.4.22.1 |
|--------------------------------------------+---------------------------|
| Asterisk Open Source | 1.6.0.3 |
|--------------------------------------------+---------------------------|
| Asterisk Business Edition | B.2.5.7 |
|--------------------------------------------+---------------------------|
| Asterisk Business Edition | C.1.10.4 |
|--------------------------------------------+---------------------------|
| Asterisk Business Edition | C.2.1.2.1 |
|--------------------------------------------+---------------------------|
| s800i (Asterisk Appliance) | 1.3.0 |
+------------------------------------------------------------------------+
+------------------------------------------------------------------------+
| Patches |
|------------------------------------------------------------------------|
| URL |Branch|
|-----------------------------------------------------------------+------|
|http://downloads.digium.com/pub/security/AST-2009-001-1.2.diff |1.2 |
|-----------------------------------------------------------------+------|
|http://downloads.digium.com/pub/security/AST-2009-001-1.4.diff |1.4 |
|-----------------------------------------------------------------+------|
|http://downloads.digium.com/pub/security/AST-2009-001-1.6.0.diff |1.6.0 |
+------------------------------------------------------------------------+
+------------------------------------------------------------------------+
| Links | http://code.google.com/p/iaxscan/ |
+------------------------------------------------------------------------+
+------------------------------------------------------------------------+
| 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-2009-001.pdf and |
| http://downloads.digium.com/pub/security/AST-2009-001.html |
+------------------------------------------------------------------------+
+------------------------------------------------------------------------+
| Revision History |
|------------------------------------------------------------------------|
| Date | Editor | Revisions Made |
|-----------------+------------------------+-----------------------------|
| 2009-01-07 | Tilghman Lesher | Initial release |
+------------------------------------------------------------------------+
Asterisk Project Security Advisory - AST-2009-001
Copyright (c) 2009 Digium, Inc. All Rights Reserved.
Permission is hereby granted to distribute and publish this advisory in its
original, unaltered form.
- --------------------------END INCLUDED TEXT--------------------
You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.
NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members. As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.
NOTE: This is only the original release of the security bulletin. It may
not be updated when updates to the original are made. If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.
Contact information for the authors of the original document is included
in the Security Bulletin above. If you have any questions or need further
information, please contact them directly.
Previous advisories and external security bulletins can be retrieved from:
http://www.auscert.org.au/render.html?cid=1980
If you believe that your computer system has been compromised or attacked in
any way, we encourage you to let us know by completing the secure National IT
Incident Reporting Form at:
http://www.auscert.org.au/render.html?it=3192
===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072
Internet Email: auscert@auscert.org.au
Facsimile: (07) 3365 7031
Telephone: (07) 3365 4417 (International: +61 7 3365 4417)
AusCERT personnel answer during Queensland business hours
which are GMT+10:00 (AEST).
On call after hours for member emergencies only.
===========================================================================
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967
iQCVAwUBSWaSUCh9+71yA2DNAQJHmAP+J+QNS3YcAkNZY3jedgQgcXssfENSOd9+
+I3LyFgSTGdTU/RPEY//vKFEw4DfEjIcP+1bvJEB3NKv7fmSDLNkitBKlfkf0Fa9
8IdTmkH722GPPqNhlOmhkd8WhHY+IdiDPi5dIeVU4GctSqrhYw5sZFnDO2TdlKhq
AgR1iKV2rNY=
=kiG3
-----END PGP SIGNATURE-----
|