Buffer overflow in Cisco Adaptive Security Appliance (Asa) Software
CVE-2021-34781
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.
Vulnerability class: Buffer Overflow
EPSS: 0.014 (70.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.
Affected products
- Cisco Adaptive Security Appliance (Asa) Software — versions n/a
- Cisco Firepower_management_center_virtual_appliance — versions 6.3.0, 6.4.0, 6.4.0.13
- Cisco Firepower_threat_defense
- Cisco Secure_firewall_threat_defense
- Cisco Sourcefire_defense_center — versions 6.3.0, 6.4.0, 6.4.0.13
Weakness classification (CWE)
References
- psirt@cisco.com (x_refsource_CISCO, vendor-advisory, Vendor Advisory)
Frequently asked questions
- What is CVE-2021-34781?
- CVE-2021-34781 is a high-severity vulnerability in Cisco Adaptive Security Appliance (Asa) Software, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 8.6/10. Published 2021-10-27.
- How severe is CVE-2021-34781?
- High severity. CVSS v3 base score is 8.6 out of 10.