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AUSCERT External Security Bulletin Redistribution
Cisco Access Point Software Arbitrary Code Execution Vulnerability
25 March 2021
AusCERT Security Bulletin Summary
Product: Cisco Access Point Software
Publisher: Cisco Systems
Operating System: Cisco
Impact/Access: Execute Arbitrary Code/Commands -- Existing Account
Reduced Security -- Existing Account
CVE Names: CVE-2021-1449
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Cisco Access Point Software Arbitrary Code Execution Vulnerability
Advisory ID: cisco-sa-ap-privesc-wEVfp8Ud
First Published: 2021 March 24 16:00 GMT
Version 1.0: Final
Workarounds: No workarounds available
Cisco Bug IDs: CSCvw45507
CVE Names: CVE-2021-1449
o A vulnerability in the boot logic of Cisco Access Points Software could
allow an authenticated, local attacker to execute unsigned code at boot
The vulnerability is due to an improper check that is performed by the area
of code that manages system startup processes. An attacker could exploit
this vulnerability by modifying a specific file that is stored on the
system, which would allow the attacker to bypass existing protections. A
successful exploit could allow the attacker to execute unsigned code at
boot time and bypass the software image verification check part of the
secure boot process of an affected device.
Note: To exploit this vulnerability, the attacker would need to have access
to the development shell (devshell) on the device.
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:
o Vulnerable Products
This vulnerability affects the following Cisco products if they are running
a vulnerable release of Cisco Access Point Software:
Aironet 1540 Series APs
Aironet 1560 Series APs
Aironet 1800 Series APs
Aironet 2800 Series APs
Aironet 3800 Series APs
Aironet 4800 APs
Catalyst 9100 APs
Catalyst IW 6300 APs
Integrated AP on 1100 Integrated Services Routers
6300 Series Embedded Services APs (ESW6300)
For information about which Cisco software releases are vulnerable, see the
Fixed Software section of this advisory.
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 any Cisco
Access Point series that is not listed in the Vulnerable Products section
of this advisory.
o APs that are running the Cisco AP-COS operating system contain a debugging
and troubleshooting mechanism known as devshell. This feature was designed
to allow secure, controlled access to the underlying Linux operating system
and debugging information.
The devshell feature can provide information that is not accessible through
existing show or debug commands. Cisco development engineers can request
low-level information through this feature without having to update the
software that is running on a device. This can provide several advantages,
such as allowing data to be collected without a reboot, which can lead to
the loss of important values that indicate error state issues and a delay
in problem resolution.
Access to the devshell feature must be explicitly authorized by the
customer; Cisco personnel cannot access this feature without customer
o There are no workarounds that address this vulnerability.
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
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
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
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
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
The process to upgrade the APs requires administrators to upgrade the
wireless controller that the APs are registered to.
Customers are advised to upgrade to an appropriate fixed software release
as indicated in the following table(s). To ensure a complete upgrade
solution, consider that this advisory is part of a collection that includes
the following advisories:
cisco-sa-aironet-info-disc-BfWqghj : Cisco Aironet Access Points
FlexConnect Upgrade Information Disclosure Vulnerability
cisco-sa-aironet-mdns-dos-E6KwYuMx : Cisco Aironet Access Points
FlexConnect Multicast DNS Denial of Service Vulnerability
cisco-sa-ap-privesc-wEVfp8Ud : Cisco Access Point Software Arbitrary
Code Execution Vulnerability
Cisco Access Points Managed by Wireless LAN Controller or Mobility Express
Cisco Wireless LAN First Fixed First Fixed Release for All
Controller Software Release for This Vulnerabilities Described in This
Release Vulnerability Collection of Advisories
8.5 and earlier 126.96.36.199 188.8.131.52
8.6 - 8.9 Migrate to a fixed 184.108.40.206
8.10 220.127.116.11 18.104.22.168
Cisco Access Points Managed by Catalyst 9800 Wireless Controller or
Embedded Wireless Controller on Catalyst Access Points (EWC)
Cisco Catalyst 9800 First Fixed First Fixed Release for All
Wireless Controller Release for This Vulnerabilities Described in This
Software Release Vulnerability Collection of Advisories
16.12 and earlier 16.12.5 16.12.5
17.1 Migrate to a 17.3.3
17.2 Migrate to a 17.3.3
17.3 17.3.3 17.3.3
17.4 Migrate to a 17.5.1 (Mar 2021)
17.5 and later Not vulnerable. Not vulnerable.
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.
o This vulnerability was found during internal security testing.
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.
| Version | Description | Section | Status | Date |
| 1.0 | Initial public release. | - | Final | 2021-MAR-24 |
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