SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2020-3273

A vulnerability in the 802.11 Generic Advertisement Service (GAS) frame processing function of Cisco Wireless LAN Controller (WLC) Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of…

HIGH 7.5EPSS 1.27%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.27%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

A vulnerability in the 802.11 Generic Advertisement Service (GAS) frame processing function of Cisco Wireless LAN Controller (WLC) Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS). The vulnerability is due to incomplete input validation of the 802.11 GAS frames that are processed by an affected device. An attacker could exploit this vulnerability by sending a crafted 802.11 GAS frame over the air to an access point (AP), and that frame would then be relayed to the affected WLC. Also, an attacker with Layer 3 connectivity to the WLC could exploit this vulnerability by sending a malicious 802.11 GAS payload in a Control and Provisioning of Wireless Access Points (CAPWAP) packet to the device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
1.27% probability · 70th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-119
Affected
cisco/5508 wireless controller firmware · cisco/5520 wireless controller firmware
Source
psirt@cisco.com
EPSS trend
0%3%5%26 October 2026: 1.27%26 October 202626 October 2026

EPSS 1.3% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.