Cisco Adaptive Security Appliance
CVE-2021-40117
A vulnerability in SSL/TLS message handler for Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability exists because incoming SSL/TLS packets are not properly processed. An attacker could exploit this vulnerability by sending a crafted SSL/TLS packet to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.
What this means for your business
- It affects Cisco Adaptive Security Appliance. It matters if your company, or a supplier that handles your data, runs it.
- An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 2% chance of attack attempts being seen in the next 30 days, ranking above 73% of all known flaws.
What to do
- 1Check whether your company or your suppliers run Cisco Adaptive Security Appliance, and which version. The affected versions are listed further down this page.
- 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.
Not sure if your company is exposed?
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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 Adaptive Security Appliance- 9.8.4.40
- Cisco Secure Firewall Threat Defense- 6.2.3.17, 6.3.0 - 6.4.0.13, 6.5.0 - 6.6.5, 6.7.0 - 6.7.0.3, 7.0.0 - 7.0.1
- Cisco Adaptive Security Appliance Software9.9.0 - 9.12.4.26, 9.13.0 - 9.14.3.9, 9.15.0 - 9.15.1.17, 9.16.0 - 9.16.2.3
- Cisco Asa 5512-X Firmware009.009\(002.085\), 009.014\(002.106\)
- Cisco Asa 5512-Xall versions
- Cisco Asa 5505 Firmware009.009\(002.085\), 009.014\(002.106\)
- Cisco Asa 5505all versions
- Cisco Asa 5515-X Firmware009.009\(002.085\), 009.014\(002.106\)
- Cisco Asa 5515-Xall versions
- Cisco Asa 5525-X Firmware009.009\(002.085\), 009.014\(002.106\)
- Cisco Asa 5525-Xall versions
- Cisco Asa 5545-X Firmware009.009\(002.085\), 009.014\(002.106\)
As listed in the NVD configuration data. Not a statement about your estate.