CVE-2023-20086 Denial of service in Cisco Adaptive Security Appliance (ASA) Software
Unauthenticated remote attackers can cause a denial of service by sending crafted ICMPv6 messages to Cisco ASA or FTD devices with IPv6 enabled.
- 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-2023-20086?
CVE-2023-20086 is a high-severity denial of service vulnerability in Cisco Adaptive Security Appliance Software, published on 1 Nov 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A vulnerability in ICMPv6 processing of 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. This vulnerability is due to improper processing of ICMPv6 messages. An attacker could exploit this vulnerability by sending crafted ICMPv6 messages to a targeted Cisco ASA or FTD system with IPv6 enabled. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.
Weakness: CWE-248
Which versions are affected by CVE-2023-20086?
It affects 2 products.
Products include Cisco Adaptive Security Appliance Software, Cisco Secure Firewall Threat Defense.
How do I fix CVE-2023-20086?
No fix has been published for CVE-2023-20086 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-2023-20086 being exploited?
There is no known exploitation of CVE-2023-20086 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-2xpc-6r4r-v2hh.