CVE-2020-3552: Cisco Aironet Access Points Ethernet Wired Clients Denial of Service Vulnerability

Severity: high (CVSS 7.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-09-24 · updated 2026-06-17
Weakness: CWE-476

Description

A vulnerability in the Ethernet packet handling of Cisco Aironet Access Points (APs) Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by connecting as a wired client to the Ethernet interface of an affected device and sending a series of specific packets within a short time frame. A successful exploit could allow the attacker to cause a NULL pointer access that results in a reload of the affected device.

Affected products

Cisco Access Points: before 16.12.4a — fixed in 16.12.4a
Cisco Mobility Express 1800 Access Point Series: 8.10(1.255)
Cisco Business Access Points: from 10.0 before 10.1.1.0 — fixed in 10.1.1.0
Cisco Wireless Lan Controller: from 8.6 before 8.10.105.0 — fixed in 8.10.105.0

How to fix

Upgrade to a fixed version: Cisco Access Points 16.12.4a; Cisco Business Access Points 10.1.1.0; Cisco Wireless Lan Controller 8.10.105.0. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2020-3552 or the next vulnerability affects your stack