Cisco Security Advisory
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CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L/E:X/RL:X/RC:X
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A vulnerability in the TCL scripting subsystem of Cisco NX-OS System Software could allow an authenticated, local attacker to escape the interactive TCL shell and gain unauthorized access to the underlying operating system of the device.
The vulnerability exists due to insufficient input validation of user-supplied files passed to the interactive TCL shell of the affected device. An attacker could exploit this vulnerability to escape the scripting sandbox and execute arbitrary commands on the underlying operating system with the privileges of the authenticated user.
To exploit this vulnerability, an attacker must have local access and be authenticated to the targeted device with administrative or tclsh execution privileges.
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-20171129-nxos5
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Vulnerable Products
This vulnerability affects the following products running Cisco NX-OS System Software:
- Multilayer Director Switches
- Nexus 2000 Series Fabric Extenders
- Nexus 3000 Series Switches
- Nexus 3500 Platform Switches
- Nexus 5000 Series Switches
- Nexus 5500 Platform Switches
- Nexus 5600 Platform Switches
- Nexus 6000 Series Switches
- Nexus 7000 Series Switches
- Nexus 7700 Series Switches
- Nexus 9000 Series Switches in standalone NX-OS mode
- Nexus 9500 R-Series Line Cards and Fabric Modules
- Unified Computing System Manager
Products Confirmed Not Vulnerable
No other Cisco products are currently known to be affected by this vulnerability.
Cisco has confirmed that this vulnerability does not affect the following products:
- Firepower 2100 Series
- Firepower 4100 Series Next-Generation Firewall
- Firepower 9300 Security Appliance
- Nexus 1000V Series Switches
- Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode
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There are no workarounds that address this vulnerability.
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For information about fixed software releases, consult the Cisco bug ID(s) at the top of this advisory.
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.
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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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This vulnerability was found during internal security testing.
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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 2017-November-29
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