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AUSCERT External Security Bulletin Redistribution
ESB-2020.3288
Cisco Catalyst 9200 Series Switches Jumbo Frame Denial of
Service Vulnerability
25 September 2020
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AusCERT Security Bulletin Summary
---------------------------------
Product: Cisco Catalyst 9200 Series Switches
Publisher: Cisco Systems
Operating System: Cisco
Impact/Access: Denial of Service -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2020-3527
Original Bulletin:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-JP-DOS-g5FfGm8y
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Cisco Catalyst 9200 Series Switches Jumbo Frame Denial of Service Vulnerability
Priority: High
Advisory ID: cisco-sa-JP-DOS-g5FfGm8y
First Published: 2020 September 24 16:00 GMT
Version 1.0: Final
Workarounds: No workarounds available
Cisco Bug IDs: CSCvr37065
CVE-2020-3527
CWE-20
CVSS Score:
8.6 AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:X/RL:X/RC:X
Summary
o A vulnerability in the Polaris kernel of Cisco Catalyst 9200 Series
Switches could allow an unauthenticated, remote attacker to crash the
device.
The vulnerability is due to insufficient packet size validation. An
attacker could exploit this vulnerability by sending jumbo frames or frames
larger than the configured MTU size to the management interface of this
device. A successful exploit could allow the attacker to crash the device
fully before an automatic recovery.
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-JP-DOS-g5FfGm8y
Affected Products
o Vulnerable Products
This vulnerability affects Cisco Catalyst 9200 Series Switches if they are
running a Cisco IOS XE Software release earlier than releases 16.12.3 and
16.9.5.
Products Confirmed Not Vulnerable
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 the following
Cisco products:
Catalyst 9000 Family (except Catalyst 9200 Series Switches)
IOS Software
IOS XR Software
NX-OS Software
Workarounds
o There are no workarounds that address this vulnerability.
Fixed Software
o 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 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
Cisco fixed this vulnerability in Cisco IOS XE Software Release 16.12.3 and
later and Release 16.9.5 and later.
Exploitation and Public Announcements
o 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.
Source
o This vulnerability was found during the resolution of a Cisco TAC support
case.
Cisco Security Vulnerability Policy
o 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.
URL
o https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/
cisco-sa-JP-DOS-g5FfGm8y
Revision History
o +----------+---------------------------+----------+--------+--------------+
| Version | Description | Section | Status | Date |
+----------+---------------------------+----------+--------+--------------+
| 1.0 | Initial public release. | - | Final | 2020-SEP-24 |
+----------+---------------------------+----------+--------+--------------+
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