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
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.014 (72.1th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 72nd percentile — 72.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.014 · newest: 0.014 · change: +0.000
Affected products
- Cisco Adaptive Security Appliance (Asa) Software
- 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
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-dos-… (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.