CVE-2020-3557: Cisco Firepower Management Center Software Denial of Service Vulnerability

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-10-21 · updated 2026-06-17
Weakness: CWE-295

Description

A vulnerability in the host input API daemon of Cisco Firepower Management Center (FMC) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper certificate validation. An attacker could exploit this vulnerability by sending a crafted data stream to the host input daemon of the affected device. A successful exploit could allow the attacker to cause the host input daemon to restart. The attacker could use repeated attacks to cause the daemon to continuously reload, creating a DoS condition for the API.

Affected products

Cisco Firepower Management Center: before 6.6.1 — fixed in 6.6.1

How to fix

Upgrade to a fixed version: Cisco Firepower Management Center 6.6.1. Check the vendor advisory for mitigations.

References

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