CVE•Published 2020-10-21•Modified 2026-08-11•1 article on news•4 live references•NVD data

CVE-2020-3563Cisco · Secure_firewall_threat_defense

Vulnerability data via NVD (ingested)

CVSS v3.1

8.6

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

EPSS percentile

Exploit Prediction Scoring System · top 30% of all CVEs

Weaknesses (CWE)

CWE-400Uncontrolled Resource Consumption

Description

A vulnerability in the packet processing functionality of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to inefficient memory management. An attacker could exploit this vulnerability by sending a large number of TCP packets to a specific port on an affected device. A successful exploit could allow the attacker to exhaust system memory, which could cause the device to reload unexpectedly. No manual intervention is needed to recover the device after it has reloaded.

Timeline

Published 2020-10-21

Modified 2026-08-11

External references

NVD MITRE Exploit-DB VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2020-3563

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Cisco Secure Firewall Threat Defense"

All exposed Cisco Secure Firewall Threat Defense instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Secure Firewall Threat Defense"

HTTP body or banner mentions "Secure Firewall Threat Defense" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2020-3563