Cisco Secure Access Control System Java Deserialization Vulnerability [CVE-2018-0147]
CVE Number – CVE-2018-0147
A vulnerability in Java deserialization used by Cisco Secure Access Control System (ACS) could allow an unauthenticated, remote attacker to execute arbitrary commands on an affected device.
The vulnerability is due to insecure deserialization of user-supplied content by the affected software. An attacker could exploit this vulnerability by sending a crafted serialized Java object. An exploit could allow the attacker to execute arbitrary commands on the device with root privileges.
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-20180307-acs2
-
Vulnerable Products
This vulnerability affects all releases of Cisco Secure ACS prior to release 5.8 patch 9. Administrators can use one of the following methods to determine which Cisco Secure ACS release is running on the device:
Cisco Secure ACS command-line Interface
The show version command can be issued from the Cisco Secure ACS CLI. The following example shows the output of the show version command for a device that is running Cisco Secure ACS 5.8.0.32 with Cumulative Patch 1 installed:
acs5x/admin# show version Cisco Application Deployment Engine OS Release: 2.2 ADE-OS Build Version: 2.2.2.013 ADE-OS System Architecture: x86_64 Copyright (c) 2005-2015 by Cisco Systems, Inc. All rights reserved. Hostname: acs5x Version information of installed applications --------------------------------------------- Cisco ACS VERSION INFORMATION ----------------------------- Version : 5.8.0.32 Internal Build ID : B.442 Patches : 5-8-0-32-1 acs5x/admin#
Cisco Secure ACS web-based InterfaceLog in to the Cisco Secure ACS web-based interface and click the About link in the top right corner of the screen.
Products Confirmed Not Vulnerable
No other Cisco products are currently known to be affected by this vulnerability.
-
The CVSSv3 score assigned to this vulnerability is based on Cisco Secure ACS releases prior to 5.8 Patch 7. Cisco Secure ACS systems running release 5.8 Patch 7 or Patch 8, require authentication in order to exploit this vulnerability. The CVSSv3 score assigned to Cisco Secure ACS systems running release 5.8 Patch 7 or Patch 8 is Base 8.8: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
-
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.htmlAdditionally, 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.htmlCustomers 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
This vulnerability is fixed in Cisco Secure ACS 5.8.0.32.9 Cumulative Patch. The software can be downloaded from the Software Center on Cisco.com by navigating to Products > Security > Network Visibility and Enforcement > Secure Access Control System > Secure Access Control System 5.8.
-
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.
-
Cisco would like to thank security researchers Mikhail Klyuchnikov and Yury Aleynov from Positive Technologies for finding and reporting this vulnerability.
Duncan is a technology professional with over 20 years experience of working in various IT roles. He has a interest in cyber security, and has a wide range of other skills in radio, electronics and telecommunications.