CVE-2021-34783
Cisco Secure Firewall Threat Defense
A vulnerability in the software-based SSL/TLS message handler of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to insufficient validation of SSL/TLS messages when the device performs software-based SSL/TLS decryption. An attacker could exploit this vulnerability by sending a crafted SSL/TLS message to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Note: Datagram TLS (DTLS) messages cannot be used to exploit this vulnerability.
Exploitation status
- A vendor advisory or patch reference has been published.
What the metrics mean
- It is reachable over a network, without needing local access.
- For an attacker who can reach it, no special conditions are needed to exploit it.
- To exploit it, no account is needed.
- Beyond that, no action by a user is required.
Scoring
- CVSS
- 8.6 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H- Weakness
- CWE-119
- Assigned by
- psirt@cisco.com
Dates
- Published
- 2021-10-27
- Last modified
- 2026-08-11
- Sources
- NVD
Affected products
- Cisco Secure Firewall Threat Defense6.4.0 - 6.4.0.13, 6.6.0 - 6.6.5, 6.7.0 - 6.7.0.3, 7.0.0 - 7.0.1
- Cisco Adaptive Security Appliance Software9.8.0 - 9.8.4.40, 9.12.0 - 9.12.4.29, 9.14.0 - 9.14.3.9, 9.15.0 - 9.15.1.17, 9.16.0 - 9.16.2
- Cisco Asa 5512-X Firmware009.016\(001\), 009.016\(001.025\)
- Cisco Asa 5512-Xall versions
- Cisco Asa 5505 Firmware009.016\(001\), 009.016\(001.025\)
- Cisco Asa 5505all versions
- Cisco Asa 5515-X Firmware009.016\(001\), 009.016\(001.025\)
- Cisco Asa 5515-Xall versions
- Cisco Asa 5525-X Firmware009.016\(001\), 009.016\(001.025\)
- Cisco Asa 5525-Xall versions
- Cisco Asa 5545-X Firmware009.016\(001\), 009.016\(001.025\)
- Cisco Asa 5545-Xall versions
As listed in the NVD configuration data. Not a statement about your estate.