Summary

• A vulnerability in the authentication service of the Cisco Unified Communications Manager IM and Presence (Unified CM IM&P) Service, Cisco TelePresence Video Communication Server (VCS), and Cisco Expressway Series could allow an unauthenticated, remote attacker to cause a service outage for users attempting to authenticate, resulting in a denial of service (DoS) condition.

  The vulnerability is due to insufficient controls for specific memory operations. An attacker could exploit this vulnerability by sending a malformed Extensible Messaging and Presence Protocol (XMPP) authentication request to an affected system. A successful exploit could allow the attacker to cause an unexpected restart of the authentication service, preventing users from successfully authenticating. Exploitation of this vulnerability does not impact users who were authenticated prior to an attack.

  Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

  This advisory is available at the following link:
  https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190605-cucm-imp-dos

Affected Products

• Vulnerable Products

  This vulnerability affects the Cisco following products if they are running a vulnerable release:

  • Expressway Series configured for Mobile and Remote Access with IM&P Service (Releases X8.1 to X12.5.2)
  • TelePresence VCS configured for Mobile and Remote Access with IM&P Service (Releases X8.1 to X12.5.2)
  • Unified Communications Manager IM&P Service (multiple releases)

  For information about which releases are vulnerable, see the Fixed Software section of this advisory.

  To determine whether Mobile and Remote Access with IM&P Service is configured on Cisco Expressway Series or Cisco TelePresence VCS, administrators can log in to the web-based management interface, choose Status > Unified Communications Status, and check the value of the IM and Presence Service entry. A product is vulnerable if the IM and Presence Service entry is present and its value is Configured.

  Products Confirmed Not Vulnerable

  Only products listed in the Vulnerable Products section of this advisory are known to be affected by this vulnerability.

  Cisco has confirmed that this vulnerability does not affect Cisco WebEx Messenger.

Workarounds

• There are no workarounds that address this vulnerability.

Fixed Software

• Cisco has released free software updates that address the vulnerability described in this advisory. Customers may only install and expect support for software versions and feature sets for which they have purchased a license. By installing, downloading, accessing, or otherwise using such software upgrades, customers agree to follow the terms of the Cisco software license:
  https://www.cisco.com/c/en/us/products/end-user-license-agreement.html

  Additionally, customers may only download software for which they have a valid license, procured from Cisco directly, or through a Cisco authorized reseller or partner. In most cases this will be a maintenance upgrade to software that was previously purchased. Free security software updates do not entitle customers to a new software license, additional software feature sets, or major revision upgrades.

  When considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories and Alerts page, to determine exposure and a complete upgrade solution.

  In all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.

  Customers Without Service Contracts

  Customers who purchase directly from Cisco but do not hold a Cisco service contract and customers who make purchases through third-party vendors but are unsuccessful in obtaining fixed software through their point of sale should obtain upgrades by contacting the Cisco TAC:
  https://www.cisco.com/c/en/us/support/web/tsd-cisco-worldwide-contacts.html

  Customers should have the product serial number available and be prepared to provide the URL of this advisory as evidence of entitlement to a free upgrade.

  Fixed Releases

  For Cisco Expressway Series and Cisco TelePresence VCS, Cisco fixed this vulnerability in Releases X12.5.3 and later.

  For Cisco Unified Communications Manager IM&P, customers are advised to upgrade to an appropriate fixed software release as indicated in the following table:

  Cisco Unified CM IM&P Service Major Release	First Fixed Release
  10.5(2) and previous releases	11.5(1) SU6 or 12.5(1)
  11.0(1)	11.5(1) SU6
  11.5(1)	11.5(1) SU6
  12.0(1)	12.5(1)
  12.5(1)	Not vulnerable

Exploitation and Public Announcements

• The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

Source

• This vulnerability was found during internal security testing.

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190605-cucm-imp-dos

Revision History

• Version	Description	Section	Status	Date
  1.1	Updated the list of Vulnerable Software Releases and related fixes.	Fixed Software	Final	2019-June-24
  1.0	Initial public release.	-	Final	2019-June-05

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