CVE-2016-6431 Denial of service in Cisco ASA Software before 9.6(1.5)
An unauthenticated remote attacker can cause a reload of the Cisco ASA firewall by sending crafted enrollment requests to the local CA feature.
- 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-2016-6431?
CVE-2016-6431 is a high-severity denial of service vulnerability in Cisco Adaptive Security Appliance Software, published on 27 Oct 2016. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A vulnerability in the local Certificate Authority (CA) feature of Cisco ASA Software before 9.6(1.5) could allow an unauthenticated, remote attacker to cause a reload of the affected system. The vulnerability is due to improper handling of crafted packets during the enrollment operation. An attacker could exploit this vulnerability by sending a crafted enrollment request to the affected system. An exploit could allow the attacker to cause the reload of the affected system. Note: Only HTTPS packets directed to the Cisco ASA interface, where the local CA is allowing user enrollment, can be used to trigger this vulnerability. This vulnerability affects systems configured in routed firewall mode and in single or multiple context mode.
Weakness: CWE-20
Which versions are affected by CVE-2016-6431?
It affects 1 product.
Products include Cisco Adaptive Security Appliance Software.
How do I fix CVE-2016-6431?
No fix has been published for CVE-2016-6431 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-2016-6431 being exploited?
There is no known exploitation of CVE-2016-6431 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-xpcq-x3x2-r3vr.