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No exploitation reported

CVE-2020-3562

No exploitation reported by the sources we read.

  • Published2020-10-21
  • WeaknessCWE-119

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A vulnerability in the SSL/TLS inspection of Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series firewalls could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper input validation for certain fields of specific SSL/TLS messages. An attacker could exploit this vulnerability by sending a malformed SSL/TLS message through an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. No manual intervention is needed to recover the device after it has reloaded.

Timeline

dates in UTC
  1. 2020-10-2119:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-3562?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-3562?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Cisco secure firewall threat defenseversion to verify
BranchAffectedFixed in
6.3= 6.3.0no fix published
6.4= 6.4.0no fix published
6.5= 6.5.0no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • CISA-ADPSSVC decisionnone2024-11-13
  • OpenCVESSVC decisionnone—
  • NVDCVSS 3.18.6read 2026-10-23
  • CNACVSS 3.08.6read 2026-10-23
  • NVDCVSS 2.07.1read 2026-10-23
  • CNAweakness (CWE)CWE-119read 2026-10-23
  • NVDweakness (CWE)CWE-119read 2026-10-23
  • FIRST EPSSEPSS score1.8 %2026-10-22

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Published
2020-10-21
Last Modified
2026-08-11
NVD status
Modified

Frequently asked questions

What is CVE-2020-3562?

A vulnerability in the SSL/TLS inspection of Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series firewalls could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper input validation for certain fields of specific SSL/TLS messages. An attacker could exploit this vulnerability by sending a malformed SSL/TLS message through an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. No manual intervention is needed to recover the device after it has reloaded.

Is CVE-2020-3562 actively exploited?

Active exploitation of CVE-2020-3562 has not been confirmed. Its EPSS score was 1.8% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-3562?

CVE-2020-3562 has a CVSS v3 base score of 8.6 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.

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