| Asterisk Project Security Advisory - AST-2012-006 
 Product         Asterisk
 Summary         Remote Crash Vulnerability in SIP Channel Driver
 Nature of Advisory   Remote Crash
 Susceptibility     Remote Authenticated Sessions
 Severity        Moderate
 Exploits Known     No
 Reported On       April 16, 2012
 Reported By       Thomas Arimont
 Posted On        April 23, 2012
 Last Updated On     April 23, 2012
 Advisory Contact    Matt Jordan < mjordan AT digium DOT com >
 CVE Name
 
 Description  A remotely exploitable crash vulnerability exists in the
 SIP channel driver if a SIP UPDATE request is processed
 within a particular window of time. For this to occur, the
 following must take place:
 
 1. The setting 'trustrpid' must be set to True
 
 2. An UPDATE request must be received after a call has been
 terminated and the associated channel object has been
 destroyed, but before the SIP dialog associated with the
 call has been destroyed. Receiving the UPDATE request
 before the call is terminated or after the SIP dialog
 associated with the call will not cause the crash
 vulnerability described here.
 
 3. The UPDATE request must be formatted with the
 appropriate headers to reflect an Asterisk connected line
 update. The information in the headers must reflect a
 different Caller ID then what was previously associated
 with the dialog.
 
 When these conditions are true, Asterisk will attempt to
 perform a connected line update with no associated channel,
 and will crash.
 
 Resolution  Asterisk now ensures a channel exists before performing a
 connected line update, when that connected line update is
 initiated via a SIP UPDATE request.
 
 In Asterisk versions not containing the fix for this issue,
 setting the 'trustrpid' setting to False will prevent this
 crash from occurring (default is False)
 
 Affected Versions
 Product               Release Series
 Asterisk Open Source             1.8.x       All versions
 Asterisk Open Source              10.x       All versions
 Asterisk Business Edition          C.3.x       All versions
 
 Corrected In
 Product                              Release
 Asterisk Open Source                   1.8.11.1, 10.3.1
 Asterisk Business Edition                     C.3.7.4
 
 Patches
 SVN URL                              Revision
 http://downloads.asterisk.org/pub/security/AST-2012-006-1.8.diff v1.8
 http://downloads.asterisk.org/pub/security/AST-2012-006-10.diff  v.10
 
 Links     https://issues.asterisk.org/jira/browse/ASTERISK-19770
 
 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-2012-006.pdf and
 http://downloads.digium.com/pub/security/AST-2012-006.html
 
 Revision History
 Date                 Editor                  Revisions Made
 04/16/2012         Matt Jordan              Initial release.
 
 Asterisk Project Security Advisory - AST-2012-006
 Copyright (c) 2012 Digium, Inc. All Rights Reserved.
 Permission is hereby granted to distribute and publish this advisory in its
 original, unaltered form
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