Cisco Security AdvisoryMedium
Advisory ID:
cisco-sa-20161207-ios
First Published:
2016 December 7 16:00 GMT
Version 1.0:
Workarounds:
Cisco Bug IDs:
CVSS Score:
Base 6.1,
Temporal 5.0
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AV:A/AC:L/Au:N/C:N/I:N/A:C/E:F/RL:OF/RC:C
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AV:A/AC:L/Au:N/C:N/I:N/A:C/E:F/RL:OF/RC:C
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A vulnerability in Cisco IOS on Catalysts Switches and Nexus 9300 Series Switches could allow an unauthenticated, adjacent attacker to cause a Layer 2 network storm.
The vulnerability occurs because the software forwards Layer 2 frames that should be consumed by the first hop. An attacker could exploit this vulnerability by injecting the Layer 2 frame into the network segment. An exploit could allow the attacker to cause a Layer 2 network storm and impact the availability of the switches.
There are workarounds that address this vulnerability.
This advisory is available at the following link:
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20161207-ios
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The following workarounds are available:
- For Cisco bug ID CSCux07028, administrators may upgrade to software version 7.0(3)l2(1) or later or disable LLDP on the attached device
- For Cisco bug ID CSCuu69332, administrators may consider enabling dot1x system-auth-control in global config mode, which may help mitigate this vulnerability depending on the Layer 2 frame that is being flooded
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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 issue was discovered when handling customer service requests and also reported to Cisco PSIRT by Denis Nolan and Nick Hilliard from INEX.
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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-December-07
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