CVE-2020-3559

Cisco Aironet Access Point Authentication Flood Denial of Service Vulnerability

HIGH

8.6

CVSS Score

Published: September 24, 2020 at 05:51 PM UTC

Updated: June 17, 2026 at 03:18 AM UTC

31 products affected across 1 vendorWireless LAN ControllerAironet Access PointAccess Points

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Severity

HIGH8.6

Exploit prediction

EPSS 1%

SSVC

No known exploit

Description

A vulnerability in Cisco Aironet Access Point (AP) Software could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to improper handling of clients that are trying to connect to the AP. An attacker could exploit this vulnerability by sending authentication requests from multiple clients to an affected device. A successful exploit could allow the attacker to cause the affected device to reload.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Access Points · Cisco

95%

v < 16.12.4a

Affected range stops below 16.12.4a, so it looks safe — our inference, not a vendor statement

cisco-catalyst-9800-40 (environment) · cisco-catalyst-9800-80 (environment) · cisco-catalyst-9800-cl (environment) · cisco-catalyst-9800-l (environment) · cisco-catalyst-9800-l-c (environment) · cisco-catalyst-9800-l-f (environment)

Aironet Access Point · Cisco

95%

17.2.0.26 8.5(151.0)

cisco-aironet-1850e (environment) · cisco-aironet-1850i (environment)

Business Access Points · Cisco

95%

10.0 ≤ v < 10.1.1.0

Affected range stops below 10.1.1.0, so it looks safe — our inference, not a vendor statement

Wireless LAN Controller · Cisco

95%

8.9 ≤ v < 8.10.112.0

Affected range stops below 8.10.112.0, so it looks safe — our inference, not a vendor statement

cisco-1111-4pwe (environment) · cisco-1111-8plteeawb (environment) · cisco-1111-8pwb (environment) · cisco-1113-8plteeawe (environment) · cisco-1113-8pmwe (environment) · cisco-1113-8pwe (environment) · cisco-1116-4plteeawe (environment) · cisco-1116-4pwe (environment) · cisco-1117-4plteeawe (environment) · cisco-1117-4pmlteeawe (environment) · cisco-1117-4pmwe (environment) · cisco-1117-4pwe (environment) · cisco-aironet-1815 (environment) · cisco-aironet-1830e (environment) · cisco-aironet-1830i (environment) · cisco-aironet-1850e (environment) · cisco-aironet-1850i (environment) · cisco-business-140ac (environment) · cisco-business-145ac (environment) · cisco-business-240ac (environment)

Business Wireless Access Point · Cisco

80%

10.0 ≤ v < 10.1.1.0

Affected range stops below 10.1.1.0, so it looks safe — our inference, not a vendor statement

1111-4Pwe · Ciscodevice

80%

All versions

1111-8Plteeawb · Ciscodevice

80%

All versions

1111-8Pwb · Ciscodevice

80%