Cisco Security Advisory
Cisco ASR 5000 Series StarOS SSH Subsystem Privilege Escalation Vulnerability
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AV:N/AC:H/Au:S/C:C/I:C/A:C/E:F/RL:OF/RC:C
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A privilege escalation vulnerability in the SSH subsystem in Cisco ASR 5000 Series devices running StarOS could allow an authenticated, remote attacker to elevate privileges. The attacker would need to have a valid and configured SSH authorized key and access to the same device from which the privileged administrator connects.
The vulnerability is due to an error that occurs when multiple users are configured to use SSH keys as the authentication mechanism. Administrative accounts configured in this manner are tied to a single remote device. A successful attack could allow a lower-privileged user to authenticate as a higher-privileged administrator if all constraints can be met.
Cisco has released software updates that address this vulnerability. Workarounds that address this vulnerability are not available.
This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160218-asr
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Workarounds are not available.
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When considering software upgrades, customers are advised to consult the Cisco Security Advisories and Responses archive at http://www.cisco.com/go/psirt and review subsequent advisories 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.
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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.
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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.
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Show LessVersion Description Section Status Date 1.0 Initial public release - Final 2016-February-18
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