CVE-2021-34781

high Cisco
CVSS v3 Base Score
8.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS Score
1.3%
Exploitation probability in 30 days
Top 31% most likely to be exploited
Attack Characteristics
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Confidentiality
None
Integrity
None
Availability
High
Published: October 27, 2021 (1775 days ago)
Last Modified: August 11, 2026
Vendor: Cisco
Source: NVD

Description

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.

CWE

CWE-119

Affected Products

cisco firepower management center virtual appliancecisco secure firewall threat defensecisco sourcefire defense center

References

🔗 tools.cisco.com 🔗 tools.cisco.com