What’s Vulnerable › Vulnerabilities

CVE-2020-3562: Cisco Firepower 2100 Series SSL/TLS Inspection Denial of Service Vulnerability

• Severity: high (CVSS 8.6 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-10-21 · updated 2026-08-11
• Weakness: CWE-119

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.

Affected products

• Cisco Firepower Threat Defense Software: 6.3.0, 6.4.0, 6.5.0

References

• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-ssl-dcrpt-dos-RYEkX4yy
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-ssl-dcrpt-dos-RYEkX4yy

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