Vulnerabilities > CVE-2021-34781 - Improper Handling of Exceptional Conditions vulnerability in Cisco products

CVSS 7.5 - HIGH

Attack vector

NETWORK

Attack complexity

LOW

Privileges required

NONE

Confidentiality impact

NONE

Integrity impact

NONE

Availability impact

HIGH

network

low complexity

cisco

CWE-755

NVD

Published: 2021-10-27

Updated: 2023-11-07

Summary

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.

Vulnerable Configurations

Part	Description	Count
Application	Cisco Cisco Sourcefire Defense Center 6.4.0 Cisco Sourcefire Defense Center 6.5.0 Cisco Sourcefire Defense Center 6.6.0 Cisco Sourcefire Defense Center 6.3.0 Cisco Sourcefire Defense Center 7.0.0 Cisco Sourcefire Defense Center 6.7.0.3 Cisco Sourcefire Defense Center 6.4.0.13 Cisco Sourcefire Defense Center 6.7.1 Cisco Firepower Threat Defense 7.0.0 Cisco Firepower Threat Defense 7.0.0.1 Cisco Firepower Threat Defense 6.7.0 Cisco Firepower Threat Defense 6.7.0.1 Cisco Firepower Threat Defense 6.7.0.2 Cisco Firepower Threat Defense 6.7.0.3 Cisco Firepower Threat Defense 6.5.0 Cisco Firepower Threat Defense 6.5.0.1 Cisco Firepower Threat Defense 6.5.0.2 Cisco Firepower Threat Defense 6.5.0.3 Cisco Firepower Threat Defense 6.5.0.4 Cisco Firepower Threat Defense 6.5.0.5 Cisco Firepower Threat Defense 6.6.0 Cisco Firepower Threat Defense 6.6.0.1 Cisco Firepower Threat Defense 6.6.1 Cisco Firepower Threat Defense 6.6.3 Cisco Firepower Threat Defense 6.6.4 Cisco Firepower Threat Defense 6.3.0 Cisco Firepower Threat Defense 6.3.0.1 Cisco Firepower Threat Defense 6.3.0.2 Cisco Firepower Threat Defense 6.3.0.3 Cisco Firepower Threat Defense 6.3.0.4 Cisco Firepower Threat Defense 6.3.0.5 Cisco Firepower Threat Defense 6.3.0.6 Cisco Firepower Threat Defense 6.4.0 Cisco Firepower Threat Defense 6.4.0.1 Cisco Firepower Threat Defense 6.4.0.2 Cisco Firepower Threat Defense 6.4.0.3 Cisco Firepower Threat Defense 6.4.0.4 Cisco Firepower Threat Defense 6.4.0.5 Cisco Firepower Threat Defense 6.4.0.6 Cisco Firepower Threat Defense 6.4.0.7 Cisco Firepower Threat Defense 6.4.0.8 Cisco Firepower Threat Defense 6.4.0.9 Cisco Firepower Threat Defense 6.4.0.10 Cisco Firepower Threat Defense 6.4.0.11 Cisco Firepower Threat Defense 6.4.0.12 Cisco Firepower Management Center Virtual Appliance 6.3.0 Cisco Firepower Management Center Virtual Appliance 6.4.0 Cisco Firepower Management Center Virtual Appliance 6.5.0 Cisco Firepower Management Center Virtual Appliance 6.6.0 Cisco Firepower Management Center Virtual Appliance 7.0.0 Cisco Firepower Management Center Virtual Appliance 6.7.0.3 Cisco Firepower Management Center Virtual Appliance 6.4.0.13 Cisco Firepower Management Center Virtual Appliance 6.7.1	53

Common Weakness Enumeration (CWE)

CWE-755 - Improper Handling of Exceptional Conditions

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-dos-rUDseW3r