AST-2008-003: Unauthenticated calls allowed from SIP channel driver

           Asterisk Project Security Advisory - AST-2008-003

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| Product | Asterisk |
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| Summary | Unauthenticated calls allowed from SIP channel |
| | driver |
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| Nature of Advisory | Authentication Bypass |
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| Susceptibility | Remote Unauthenticated Sessions |
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| Severity | Major |
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| Exploits Known | No |
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| Reported On | March 12, 2008 |
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| Reported By | Jason Parker <[email protected]> |
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| Posted On | March 18, 2008 |
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| Last Updated On | March 18, 2008 |
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| Advisory Contact | Jason Parker <[email protected]> |
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| CVE Name | CVE-2008-1332 |
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| Description | Unauthenticated calls can be made via the SIP channel |
| | driver using an invalid From header. This acts similarly |
| | to the SIP configuration option 'allowguest=yes', in |
| | that calls with a specially crafted From header would be |
| | sent to the PBX in the context specified in the general |
| | section of sip.conf. |
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| Resolution | A fix has been added which checks for the option |
| | 'allowguest' to be enabled before determining that |
| | authentication is not required. |
| | |
| | As a workaround, modify the context in the general |
| | section of sip.conf to point to a non-trusted location |
| | (example: a non-existent context, or a context that does |
| | nothing but hang up the call). |
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| Links | |
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| 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| This document may be superseded by later versions; if so, the latest |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-2008-003.pdf and |
| http://downloads.digium.com/pub/security/AST-2008-003.html |
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           Asterisk Project Security Advisory - AST-2008-003
          Copyright (c) 2008 Digium, Inc. All Rights Reserved.

Permission is hereby granted to distribute and publish this advisory in its
original, unaltered form.