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AUSCERT External Security Bulletin Redistribution
ESB-2020.0339
Cisco Small Business Switches Denial of Service Vulnerability
30 January 2020
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: 200 Series Smart Switches
300 Series Managed Switches
500 Series Stackable Managed Switches
Publisher: Cisco Systems
Operating System: Cisco
Impact/Access: Denial of Service -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2020-3147
Original Bulletin:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-smlbus-switch-dos-R6VquS2u
- --------------------------BEGIN INCLUDED TEXT--------------------
Cisco Small Business Switches Denial of Service Vulnerability
Priority: High
Advisory ID: cisco-sa-smlbus-switch-dos-R6VquS2u
First Published: 2020 January 29 16:00 GMT
Version 1.0: Final
Workarounds: No workarounds availableCisco Bug IDs: CSCvs79718CSCvs80055CSCvs80085
CVE-2020-3147
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 [CVE-2020-3147_su]
A vulnerability in the web UI of Cisco Small Business Switches could allow
an unauthenticated, remote attacker to cause a denial of service (DoS)
condition on an affected device.
The vulnerability is due to improper validation of requests sent to the web
interface. An attacker could exploit this vulnerability by sending a
malicious request to the web interface of an affected device. A successful
exploit could allow the attacker to cause an unexpected reload of the
device, resulting in a DoS condition.
Cisco has released software updates that address the vulnerability
described in this advisory. 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-smlbus-switch-dos-R6VquS2u
[/CVE-2020-3147_su]
Affected Products
o [CVE-2020-3147_ap]
[/CVE-2020-3147_ap]
Vulnerable Products
[CVE-2020-3147_vp]
This vulnerability affects the following Cisco products if they are running
a firmware release earlier than 1.3.7.18:
200 Series Smart Switches
300 Series Managed Switches
500 Series Stackable Managed Switches
[/CVE-2020-3147_vp]
Products Confirmed Not Vulnerable
[CVE-2020-3147_nv]
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:
250 Series Smart Switches
350 Series Managed Switches
350X Series Stackable Managed Switches
550X Series Stackable Managed Switches
[/CVE-2020-3147_nv]
Workarounds
o [CVE-2020-3147_wa]
There are no workarounds that address this vulnerability.
[/CVE-2020-3147_wa]
Fixed Software
o [CVE-2020-3147_fs]
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 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.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.
[/CVE-2020-3147_fs]
[CVE-2020-3147_fr]
Fixed Releases
Cisco fixed this vulnerability in firmware Release 1.3.7.18 for the
following Cisco products:
200 Series Smart Switches
300 Series Managed Switches
500 Series Stackable Managed Switches
To download the firmware from the Software Center on Cisco.com, do the
following:
1. Click Browse all .
2. Choose Switches > LAN Switches - Small Business .
3. Choose a specific product from the right pane of the product selector.
4. Choose Smart Switch Firmware or Switch Firmware .
5. Choose a release from the left pane of the page.
[/CVE-2020-3147_fr]
Exploitation and Public Announcements
o [CVE-2020-3147_ex]
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.
[/CVE-2020-3147_ex]
Source
o [CVE-2020-3147_vs]
Cisco would like to thank Ken Pyle of DFDR Consulting LLC for reporting
this vulnerability.
[/CVE-2020-3147_vs]
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-smlbus-switch-dos-R6VquS2u
Revision History
o +----------+---------------------------+----------+--------+--------------+
| Version | Description | Section | Status | Date |
+----------+---------------------------+----------+--------+--------------+
| 1.0 | Initial public release. | - | Final | 2020-JAN-29 |
+----------+---------------------------+----------+--------+--------------+
- --------------------------END INCLUDED TEXT--------------------
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