CVE-2020-3583 Cross-site scripting in Cisco Adaptive Security Appliance (ASA) Software
Unauthenticated attackers can execute arbitrary scripts or access sensitive data via XSS in Cisco ASA/FTD web interfaces with specific AnyConnect/WebVPN configurations.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2020-3583?
CVE-2020-3583 is a medium-severity cross-site scripting vulnerability in Cisco Adaptive Security Appliance Software, published on 21 Oct 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Multiple vulnerabilities in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct cross-site scripting (XSS) attacks against a user of the web services interface of an affected device. The vulnerabilities are due to insufficient validation of user-supplied input by the web services interface of an affected device. An attacker could exploit these vulnerabilities by persuading a user of the interface to click a crafted link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the interface or allow the attacker to access sensitive, browser-based information. Note: These vulnerabilities affect only specific AnyConnect and WebVPN configurations. For more information, see the Vulnerable Products section.
Weakness: CWE-79
Which versions are affected by CVE-2020-3583?
It affects 3 products.
Products include Cisco Adaptive Security Appliance Software, Cisco Firepower Threat Defense, Cisco Secure Firewall Threat Defense.
How do I fix CVE-2020-3583?
No fix has been published for CVE-2020-3583 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2020-3583 being exploited?
There is no known exploitation of CVE-2020-3583 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-35fr-79wv-f9r8.