CVE-2021-40117 Denial of service in Cisco Adaptive Security Appliance (ASA) Software
Unauthenticated remote attackers can cause a denial of service on Cisco ASA and FTD devices by sending crafted SSL/TLS packets, requiring immediate patching.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-40117?
CVE-2021-40117 is a high-severity denial of service vulnerability in Cisco Adaptive Security Appliance, published on 27 Oct 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2021-40117?
It affects 11 products.
Products include Cisco Adaptive Security Appliance, Cisco Adaptive Security Appliance Software, Cisco Asa 5505 Firmware, Cisco Asa 5512-X Firmware, Cisco Asa 5515-X Firmware, Cisco Asa 5525-X Firmware and 5 more.
How do I fix CVE-2021-40117?
No fix has been published for CVE-2021-40117 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-40117 being exploited?
There is no known exploitation of CVE-2021-40117 in the wild and no public exploit code.
Other vulnerabilities in Cisco Adaptive Security Appliance
- CVE-2021-1573 Denial of service in Cisco Adaptive Security Appliance Software
- CVE-2021-34793 Denial of service in Cisco Adaptive Security Appliance (ASA) Software
- CVE-2021-40118 Denial of service in Cisco Adaptive Security Appliance (ASA) Software
- CVE-2020-3304 Denial of service in Cisco Adaptive Security Appliance (ASA) Software
- CVE-2020-3436 File upload in Cisco Adaptive Security Appliance (ASA) Software
Sources
Also known as GHSA-x7cf-699f-fpwc.