CVE-2020-3558: A vulnerability in the web-based management interface of Cisco Firepower Management Center (FMC) Software could allow an unauthenticated, remote attac...

Description

A vulnerability in the web-based management interface of Cisco Firepower Management Center (FMC) Software could allow an unauthenticated, remote attacker to redirect a user to a malicious web page. The vulnerability is due to improper input validation of the parameters of an HTTP request. An attacker could exploit this vulnerability by intercepting an HTTP request from a user. A successful exploit could allow the attacker to modify the HTTP request to cause the interface to redirect the user to a specific, malicious URL. This type of vulnerability is known as an open redirect attack and is used in phishing attacks that get users to unknowingly visit malicious sites.

Metrics

CVSS 3.1

6.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

0.79%

51.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Cisco	Secure Firewall Management Center	>= 6.2.0, <= 6.2.3.16
Cisco	Secure Firewall Management Center	>= 6.3.0, <= 6.3.0.5
Cisco	Secure Firewall Management Center	>= 6.4.0, <= 6.4.0.9
Cisco	Secure Firewall Management Center	>= 6.5.0, <= 6.5.0.4

References

Timeline

Published: Oct 21, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-3558?

A vulnerability in the web-based management interface of Cisco Firepower Management Center (FMC) Software could allow an unauthenticated, remote attacker to redirect a user to a malicious web page. The vulnerability is due to improper input validation of the parameters of an HTTP request. An attacker could exploit this vulnerability by intercepting an HTTP request from a user. A successful exploit could allow the attacker to modify the HTTP request to cause the interface to redirect the user to a specific, malicious URL. This type of vulnerability is known as an open redirect attack and is used in phishing attacks that get users to unknowingly visit malicious sites.

How severe is CVE-2020-3558?

CVE-2020-3558 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.79% probability of exploitation in the next 30 days.

How do I fix CVE-2020-3558?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.