Product

Asterisk

Summary

Asterisk Susceptibility to POODLE Vulnerability

Nature of Advisory

Unauthorized Data Disclosure

Susceptibility

Remote Unauthenticated Sessions

Severity

Medium

Exploits Known

No

Reported On

16 October 2014

Reported By

abelbeck

Posted On

20 October 2014

Last Updated On

October 20, 2014

Advisory Contact

Matt Jordan <mjordan AT digium DOT com>

CVE Name

CVE-2014-3566

Description

The POODLE vulnerability – described under CVE-2014-3566 – is described at https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-3566. This advisory describes the Asterisk's project susceptibility to this vulnerability.

The POODLE vulnerability consists of two issues:

1) A vulnerability in the SSL protocol version 3.0. This vulnerability has no known solution.

2) The ability to force a fallback to SSLv3 when a TLS connection is negotiated.

Asterisk is susceptible to both portions of the vulnerability in different places.

1) The res_jabber and res_xmpp module both use SSLv3 exclusively, and are hence susceptible to POODLE.

2) The core TLS handling, used by the chan_sip channel driver, Asterisk Manager Interface (AMI), and the Asterisk HTTP server, defaults to allowing SSLv3/SSLv2 fallback. This allows a MITM to potentially force a connection to fallback to SSLv3, exposing it to the POODLE vulnerability.

Resolution

Asterisk has been patched such that it no longer uses SSLv3 for the res_jabber/res_xmpp modules. Additionally, when the encryption method is not specified, the default handling in the TLS core no longer allows for a fallback to SSLv3 or SSLv2.

1) Users of Asterisk's res_jabber or res_xmpp modules should upgrade to the versions of Asterisk specified in this advisory.

2) Users of Asterisk's chan_sip channel driver, AMI, and HTTP server may set the “tlsclientmethod” or “sslclientmethod” to “tlsv1” to force TLSv1 as the only allowed encryption method. Alternatively, they may also upgrade to the versions of Asterisk specified in this advisory. Users of Asterisk are encouraged to NOT specify “sslv2” or “sslv3”. Doing so will now emit a WARNING.

Affected Versions

Product

Release Series

Asterisk Open Source

1.8.x

All versions

Asterisk Open Source

11.x

All versions

Asterisk Open Source

12.x

All versions

Certified Asterisk

1.8.28

All versions

Certified Asterisk

11.6

All versions

Corrected In

Product

Release

Asterisk Open Source

1.8.31.1, 11.13.1, 12.6.1

Certified Asterisk

1.8.28-cert2, 11.6-cert7

Patches

SVN URL

Revision

http://downloads.asterisk.org/pub/security/AST-2014-011-1.8.diff

Asterisk 1.8

http://downloads.asterisk.org/pub/security/AST-2014-011-11.diff

Asterisk 11

http://downloads.asterisk.org/pub/security/AST-2014-011-12.diff

Asterisk 12

http://downloads.asterisk.org/pub/security/AST-2014-011-1.8.28.diff

Certified Asterisk 1.8.28

http://downloads.asterisk.org/pub/security/AST-2014-011-11.6.diff

Certified Asterisk 11.6

Links

https://issues.asterisk.org/jira/browse/ASTERISK-24425

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-2014-011.pdf and http://downloads.digium.com/pub/security/AST-2014-011.html

Revision History

Date

Editor

Revisions Made

October 19

Matt Jordan

Initial Revision