SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2020-3564

A vulnerability in the FTP inspection engine of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass FTP inspection.

MEDIUM 5.3EPSS 1.34%

Does this matter?

Lower severity and a low EPSS score (1.34%). Track it; it rarely justifies an emergency change on its own.

Description

A vulnerability in the FTP inspection engine of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass FTP inspection. The vulnerability is due to ineffective flow tracking of FTP traffic. An attacker could exploit this vulnerability by sending crafted FTP traffic through an affected device. A successful exploit could allow the attacker to bypass FTP inspection and successfully complete FTP connections.

CVSS 3.1
5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
EPSS
1.34% probability · 71th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-284, CWE-436
Affected
cisco/adaptive security appliance · cisco/secure firewall threat defense · cisco/adaptive security appliance software
Source
psirt@cisco.com
EPSS trend
0%3%5%26 October 2026: 1.34%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.