CVE-2021-1422 Denial of service in Cisco Adaptive Security Appliance (ASA) Software
An attacker can cause a denial of service by sending malicious IPsec packets, crashing Cisco ASA and FTD devices.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-1422?
CVE-2021-1422 is a high-severity denial of service vulnerability in Cisco Adaptive Security Appliance Software, published on 16 Jul 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A vulnerability in the software cryptography module of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker or an unauthenticated attacker in a man-in-the-middle position to cause an unexpected reload of the device that results in a denial of service (DoS) condition. The vulnerability is due to a logic error in how the software cryptography module handles specific types of decryption errors. An attacker could exploit this vulnerability by sending malicious packets over an established IPsec connection. A successful exploit could cause the device to crash, forcing it to reload. Important: Successful exploitation of this vulnerability would not cause a compromise of any encrypted data. Note: This vulnerability affects only Cisco ASA Software Release 9.16.1 and Cisco FTD Software Release 7.0.0.
Weakness: CWE-617
Which versions are affected by CVE-2021-1422?
It affects 2 products.
Products include Cisco Adaptive Security Appliance Software, Cisco Secure Firewall Threat Defense.
How do I fix CVE-2021-1422?
No fix has been published for CVE-2021-1422 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-2021-1422 being exploited?
There is no known exploitation of CVE-2021-1422 in the wild and no public exploit code.
Other vulnerabilities in Cisco Adaptive Security Appliance Software
- CVE-2025-20333 Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Buffer Overflow
- CVE-2016-6366 Cisco Adaptive Security Appliance (ASA) SNMP Buffer Overflow
- CVE-2026-20349 Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Heap Inspection
- CVE-2024-20353 Cisco ASA and FTD Denial of Service
- CVE-2016-6367 Cisco Adaptive Security Appliance (ASA) CLI Remote Code Execution
All Cisco Adaptive Security Appliance Software vulnerabilities
Sources
Also known as GHSA-jcpc-3vwc-j47q.