CVE-2020-3125 Cisco Adaptive Security Appliance Software Kerberos Authentication Bypass Vulnerability
An unauthenticated remote attacker can bypass Kerberos authentication on Cisco ASA devices by spoofing the KDC response, potentially gaining unauthorized access.
- 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-2020-3125?
CVE-2020-3125 is a high-severity authentication bypass vulnerability in Cisco Adaptive Security Appliance Software, published on 6 May 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A vulnerability in the Kerberos authentication feature of Cisco Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to impersonate the Kerberos key distribution center (KDC) and bypass authentication on an affected device that is configured to perform Kerberos authentication for VPN or local device access. The vulnerability is due to insufficient identity verification of the KDC when a successful authentication response is received. An attacker could exploit this vulnerability by spoofing the KDC server response to the ASA device. This malicious response would not have been authenticated by the KDC. A successful attack could allow an attacker to bypass Kerberos authentication.
Weakness: CWE-287
Which versions are affected by CVE-2020-3125?
It affects 13 products.
Products include Cisco Adaptive Security Appliance Software, Cisco Asa 5505 Firmware, Cisco Asa 5510 Firmware, Cisco Asa 5512-X Firmware, Cisco Asa 5515-X Firmware, Cisco Asa 5520 Firmware and 7 more.
How do I fix CVE-2020-3125?
No fix has been published for CVE-2020-3125 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2020-3125 being exploited?
There is no known exploitation of CVE-2020-3125 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-9x68-6g6c-vj48.