CVE-2021-1402

A vulnerability in the software-based SSL/TLS message handler of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to insufficient validation of SSL/TLS messages when the device performs software-based SSL decryption. An attacker could exploit this vulnerability by sending a crafted SSL/TLS message through an affected device. SSL/TLS messages sent to an affected device do not trigger this vulnerability. A successful exploit could allow the attacker to cause a process to crash. This crash would then trigger a reload of the device. No manual intervention is needed to recover the device after the reload.

• CWE-119
• CWE-20

• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-ssl-decrypt-dos-DdyLuK6cVendor Advisory
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-ssl-decrypt-dos-DdyLuK6cVendor Advisory

Published

Apr 29, 2021

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2021-1396Multiple vulnerabilities in Cisco Application Services Engin…6.5
• CVE-2021-1397A vulnerability in the web-based management interface of Cis…6.1
• CVE-2021-1398A vulnerability in the boot logic of Cisco IOS XE Software c…6.8
• CVE-2021-1399A vulnerability in the Self Care Portal of Cisco Unified Com…4.3
• CVE-2021-1400Multiple vulnerabilities in the web-based management interfa…8.8
• CVE-2021-1401Multiple vulnerabilities in the web-based management interfa…7.2
• CVE-2021-1403A vulnerability in the web UI feature of Cisco IOS XE Softwa…7.4
• CVE-2021-1404A vulnerability in the PDF parsing module in Clam AntiVirus …7.5
• CVE-2021-1405A vulnerability in the email parsing module in Clam AntiViru…7.5
• CVE-2021-1406A vulnerability in Cisco Unified Communications Manager (Uni…4.9
• CVE-2021-1407Multiple vulnerabilities in the web-based management interfa…6.1
• CVE-2021-1408Multiple vulnerabilities in the web-based management interfa…6.1