vulnerability
Cisco FTD: CVE-2021-1402: Cisco Firepower Threat Defense Software SSL Decryption Policy Denial of Service Vulnerability
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 8 | (AV:N/AC:L/Au:N/C:N/I:N/A:C) | Apr 28, 2021 | Jan 19, 2026 | Mar 31, 2026 |
Description
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.
Solution
References
- CVE-2021-1402
- https://attackerkb.com/topics/CVE-2021-1402
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-ssl-decrypt-dos-DdyLuK6c
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-6869
- CISCO-cisco-sa-ftd-ssl-decrypt-dos-DdyLuK6c
- CWE-119
- CWE-20
- EUVD-EUVD-2021-6869
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