A vulnerability in the processing of SSH connections for multi-instance deployments of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on the affected device. This vulnerability is due to a lack of proper error handling when an SSH session fails to be established. An attacker could exploit this vulnerability by sending a high rate of crafted SSH connections to the instance. A successful exploit could allow the attacker to cause resource exhaustion, which causes a DoS condition on the affected device. The device must be manually reloaded to recover.
History

Tue, 11 Aug 2026 20:00:00 +0000

Type Values Removed Values Added
First Time appeared Cisco secure Firewall Threat Defense
CPEs cpe:2.3:a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:* cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:*
Vendors & Products Cisco firepower Threat Defense
Cisco secure Firewall Threat Defense

Thu, 07 Nov 2024 22:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


cve-icon MITRE

Status: PUBLISHED

Assigner: cisco

Published:

Updated: 2024-11-07T21:46:12.549Z

Reserved: 2021-06-15T00:00:00.000Z

Link: CVE-2021-34781

cve-icon Vulnrichment

Updated: 2024-08-04T00:19:48.142Z

cve-icon NVD

Status : Modified

Published: 2021-10-27T19:15:08.233

Modified: 2026-08-11T19:33:44.513

Link: CVE-2021-34781

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.