CVE-2020-3166 Cisco FXOS Software CLI Arbitrary File Read and Write Vulnerability
An authenticated local attacker can read or write arbitrary files on the underlying OS via crafted CLI arguments in Cisco FXOS.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2020-3166?
CVE-2020-3166 is a medium-severity path traversal vulnerability in Cisco Adaptive Security Appliance Software, published on 26 Feb 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A vulnerability in the CLI of Cisco FXOS Software could allow an authenticated, local attacker to read or write arbitrary files on the underlying operating system (OS). The vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by including crafted arguments to a specific CLI command. A successful exploit could allow the attacker to read or write to arbitrary files on the underlying OS.
Weakness: CWE-20
Which versions are affected by CVE-2020-3166?
It affects 3 products.
Products include Cisco Adaptive Security Appliance Software, Cisco Firepower Extensible Operating System, Cisco Secure Firewall Threat Defense.
How do I fix CVE-2020-3166?
No fix has been published for CVE-2020-3166 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2020-3166 being exploited?
There is no known exploitation of CVE-2020-3166 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-p69f-j8x7-477j.