A vulnerability in the XCP Router service of the Cisco Unified Communications Manager IM & Presence Service (CUCM IM&P) and the Cisco TelePresence Video Communication Server (VCS) and Expressway could allow an unauthenticated, remote attacker to cause a temporary service outage for all IM&P users, resulting in a denial of service (DoS) condition. The vulnerability is due to improper validation of user-supplied input. An attacker could exploit this vulnerability by sending a malicious IPv4 or IPv6 packet to an affected device on TCP port 7400. An exploit could allow the attacker to overread a buffer, resulting in a crash and restart of the XCP Router service. 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://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180815-ucmimps-dos
A vulnerability in the XCP Router service of the Cisco Unified Communications Manager IM & Presence Service (CUCM IM&P) and the Cisco TelePresence Video Communication Server (VCS) and Expressway could allow an unauthenticated, remote attacker to cause a temporary service outage for all IM&P users, resulting in a denial of service (DoS) condition.
The vulnerability is due to improper validation of user-supplied input. An attacker could exploit this vulnerability by sending a malicious IPv4 or IPv6 packet to an affected device on TCP port 7400. An exploit could allow the attacker to overread a buffer, resulting in a crash and restart of the XCP Router service.
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://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180815-ucmimps-dos
This vulnerability affects all releases of the following Cisco products prior to their respective first fixed release:
Identifying the Unified Communications Manager IM & Presence Service Version
To determine whether a vulnerable version of the Cisco Unified Communications Manager IM & Presence Service is running on a device, administrators can use the show version active command in the command-line interface (CLI) for the device.
The following example shows the output from a device that is running Cisco Unified Communications Manager IM & Presence Service version 11.5(1):
admin: show version active
Active Master Version: 11.5.1.10000-4
Active Version Installed Software Options:
No Installed Software Options Found.
Identifying the Cisco TelePresence VCS and Expressway Version
Administrators can log in to the web-based GUI of Cisco TelePresence VCS and Expressway and view the current version in the lower-right corner in the Version field. Alternatively, administrators can view the Software version field by navigating to Status > System > Information.
Identifying the Cisco TelePresence VCS and Expressway Unified Communications mode
To identify the current Unified Communications mode on Cisco TelePresence VCS and Expressway, administrators can log in to the web-based GUI of the system and look for the current setting of the Unified Communications mode option under Configuration > Unified Communications > Configuration.
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 Service.
There are no workarounds that address this vulnerability.
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
Customers should upgrade to an appropriate release as indicated in the following tables:
Cisco Unified Communications Manager IM & Presence Service
| Cisco CUCM IM&P Service Major Release |
First Fixed Release |
|---|---|
| 10.5(1) and earlier |
Migrate to 11.5(1)SU4 |
| 10.5(2) | 10.5(2)SU (Future release) |
| 11.0(1) | Migrate to 11.5(1)SU4 |
| 11.5(1) | 11.5(1)SU4 |
| 12.0(1) | 12.0.1.21000-31 |
1 This release is not publicly available on Cisco.com. Please contact Cisco TAC if you need this release.
Cisco TelePresence Video Communication Server (VCS) and Expressway
| Cisco TelePresence VCS and Expressway Major Release |
First Fixed Release |
|---|---|
| X7 and earlier |
Migrate to X8.11 |
| X8 | X8.11 |
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.
This vulnerability was found during the resolution of a Cisco TAC support case.
To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.
| Version | Description | Section | Status | Date |
|---|---|---|---|---|
| 1.1 | Corrected the first fixed release for CUCM IM&P 12.0(1) | Fixed Software | Final | 2018-September-04 |
| 1.0 | Initial public release. | - | Final | 2018-August-15 |
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