CVE-2020-3564
MEDIUMDescription
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.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Exploit Intelligence
Moderate risk: more likely to be exploited than 69% of all known CVEs.
References
Related Vulnerabilities
Other CWE-284 (Improper Access Control) vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2023-27350 | Critical | 9.8 | 100% | KEV + Ransom | Fix |
| CVE-2019-1653 | High | 7.5 | 100% | KEV | - |
| CVE-2023-23752 | Medium | 5.3 | 100% | KEV | Fix |
| CVE-2023-29298 | High | 7.5 | 100% | KEV | - |
| CVE-2023-38205 | High | 7.5 | 100% | KEV | - |
| CVE-2024-27348 | Critical | 9.8 | 99% | KEV | Fix |
Common questions
How do I fix CVE-2020-3564?
Published advisories record a fix for 4 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.
Is CVE-2020-3564 being actively exploited?
Not that we know of. CVE-2020-3564 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 1.3% is the estimated probability that it will be exploited in the next 30 days. That is higher than 69% of all scored CVEs.
How severe is CVE-2020-3564?
CVE-2020-3564 has a CVSS v3 base score of 5.3, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2020-3564 affect?
Published advisories record a fix for adaptive security appliance (NVD), adaptive security appliance software (NVD), firepower threat defense (NVD), secure firewall threat defense (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-08-11.