Asterisk Guru

AsteriskGuru Archives
Mailing List Archives

FAQ

Memberlist

Usergroups

Profile

[asterisk-announce] AST-2009-003: SIP responses expose valid

AsteriskGuru Archives Forum Index -> Asterisk-Announce

View previous topic :: View next topic

Author

Message

security at asterisk.org
Guest

Posted: Thu Apr 02, 2009 6:19 pm Post subject: [asterisk-announce] AST-2009-003: SIP responses expose valid

Asterisk Project Security Advisory - AST-2009-003 +------------------------------------------------------------------------+ \| Product \| Asterisk \| \|--------------------+---------------------------------------------------\| \| Summary \| SIP responses expose valid usernames \| \|--------------------+---------------------------------------------------\| \| Nature of Advisory \| Information leak \| \|--------------------+---------------------------------------------------\| \| Susceptibility \| Remote Unauthenticated Sessions \| \|--------------------+---------------------------------------------------\| \| Severity \| Minor \| \|--------------------+---------------------------------------------------\| \| Exploits Known \| No \| \|--------------------+---------------------------------------------------\| \| Reported On \| February 23, 2009 \| \|--------------------+---------------------------------------------------\| \| Reported By \| Gentoo Linux Project: Kerin Millar ( kerframil on \| \| \| irc.freenode.net ) and Fergal Glynn < FGlynn AT \| \| \| veracode DOT com > \| \|--------------------+---------------------------------------------------\| \| Posted On \| April 2, 2009 \| \|--------------------+---------------------------------------------------\| \| Last Updated On \| April 2, 2009 \| \|--------------------+---------------------------------------------------\| \| Advisory Contact \| Tilghman Lesher < tlesher AT digium DOT com > \| \|--------------------+---------------------------------------------------\| \| CVE Name \| CVE-2008-3903 \| +------------------------------------------------------------------------+ +------------------------------------------------------------------------+ \| Description \| In 2006, the Asterisk maintainers made it more difficult \| \| \| to scan for valid SIP usernames by implementing an \| \| \| option called "alwaysauthreject", which should return a \| \| \| 401 error on all replies which are generated for users \| \| \| which do not exist. While this was sufficient at the \| \| \| time, due to ever increasing compliance with RFC 3261, \| \| \| the SIP specification, that is no longer sufficient as a \| \| \| means towards preventing attackers from checking \| \| \| responses to verify whether a SIP account exists on a \| \| \| machine. \| \| \| \| \| \| What we have done is to carefully emulate exactly the \| \| \| same responses throughout possible dialogs, which should \| \| \| prevent attackers from gleaning this information. All \| \| \| invalid users, if this option is turned on, will receive \| \| \| the same response throughout the dialog, as if a \| \| \| username was valid, but the password was incorrect. \| \| \| \| \| \| It is important to note several things. First, this \| \| \| vulnerability is derived directly from the SIP \| \| \| specification, and it is a technical violation of RFC \| \| \| 3261 (and subsequent RFCs, as of this date), for us to \| \| \| return these responses. Second, this attack is made much \| \| \| more difficult if administrators avoided creating \| \| \| all-numeric usernames and especially all-numeric \| \| \| passwords. This combination is extremely vulnerable for \| \| \| servers connected to the public Internet, even with this \| \| \| patch in place. While it may make configuring SIP \| \| \| telephones easier in the short term, it has the \| \| \| potential to cause grief over the long term. \| +------------------------------------------------------------------------+ +------------------------------------------------------------------------+ \| Resolution \| Upgrade to one of the versions below, or apply one of the \| \| \| patches specified in the Patches section. \| +------------------------------------------------------------------------+ +------------------------------------------------------------------------+ \| Affected Versions \| \|------------------------------------------------------------------------\| \| Product \| Release \| \| \| \| Series \| \| \|----------------------------+------------+------------------------------\| \| Asterisk Open Source \| 1.2.x \| All versions prior to 1.2.32 \| \|----------------------------+------------+------------------------------\| \| Asterisk Open Source \| 1.4.x \| All versions prior to \| \| \| \| 1.4.24.1 \| \|----------------------------+------------+------------------------------\| \| Asterisk Open Source \| 1.6.0.x \| All versions prior to \| \| \| \| 1.6.0.8 \| \|----------------------------+------------+------------------------------\| \| 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.2.5.8 \| \|----------------------------+------------+------------------------------\| \| Asterisk Business Edition \| C.1.x.x \| All versions prior to \| \| \| \| C.1.10.5 \| \|----------------------------+------------+------------------------------\| \| Asterisk Business Edition \| C.2.x.x \| All versions prior to \| \| \| \| C.2.3.3 \| \|----------------------------+------------+------------------------------\| \| AsteriskNOW \| 1.5 \| Not affected \| \|----------------------------+------------+------------------------------\| \| s800i (Asterisk Appliance) \| 1.3.x \| All versions prior to \| \| \| \| 1.3.0.2 \| +------------------------------------------------------------------------+ +------------------------------------------------------------------------+ \| Corrected In \| \|------------------------------------------------------------------------\| \| Product \| Release \| \|---------------------------------------------+--------------------------\| \| Asterisk Open Source \| 1.2.32 \| \|---------------------------------------------+--------------------------\| \| Asterisk Open Source \| 1.4.24.1 \| \|---------------------------------------------+--------------------------\| \| Asterisk Open Source \| 1.6.0.8 \| \|---------------------------------------------+--------------------------\| \| Asterisk Business Edition \| B.2.5.8 \| \|---------------------------------------------+--------------------------\| \| Asterisk Business Edition \| C.1.10.5 \| \|---------------------------------------------+--------------------------\| \| Asterisk Business Edition \| C.2.3.3 \| \|---------------------------------------------+--------------------------\| \| s800i (Asterisk Appliance) \| 1.3.0.2 \| +------------------------------------------------------------------------+ +------------------------------------------------------------------------+ \| Patches \| \|------------------------------------------------------------------------\| \| Patch URL \|Version\| \|----------------------------------------------------------------+-------\| \|http://downloads.digium.com/pub/asa/AST-2009-003-1.2.diff.txt \| 1.2 \| \|----------------------------------------------------------------+-------\| \|http://downloads.digium.com/pub/asa/AST-2009-003-1.4.diff.txt \| 1.4 \| \|----------------------------------------------------------------+-------\| \|http://downloads.digium.com/pub/asa/AST-2009-003-1.6.0.diff.txt \| 1.6.0 \| \|----------------------------------------------------------------+-------\| \|http://downloads.digium.com/pub/asa/AST-2009-003-1.6.1.diff.txt \| 1.6.1 \| +------------------------------------------------------------------------+ +------------------------------------------------------------------------+ \| Links \| http://www.faqs.org/rfcs/rfc3261.html \| +------------------------------------------------------------------------+ +------------------------------------------------------------------------+ \| 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-2009-003.pdf and \| \| http://downloads.digium.com/pub/security/AST-2009-003.html \| +------------------------------------------------------------------------+ +------------------------------------------------------------------------+ \| Revision History \| \|------------------------------------------------------------------------\| \| Date \| Editor \| Revisions Made \| \|-----------------+------------------------+-----------------------------\| \| 2009-04-02 \| Tilghman Lesher \| Initial release \| +------------------------------------------------------------------------+ Asterisk Project Security Advisory - AST-2009-003 Copyright (c) 2009 Digium, Inc. All Rights Reserved. Permission is hereby granted to distribute and publish this advisory in its original, unaltered form. _______________________________________________ --Bandwidth and Colocation Provided by http://www.api-digital.com-- asterisk-announce mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-announce

Display posts from previous:

AsteriskGuru Archives Forum Index -> Asterisk-Announce	All times are GMT
Page 1 of 1

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum