CVE-2023-20155: A vulnerability in a logging API in Cisco Firepower Management Center (FMC) Software could allow an unauthenticated, remote attacker to cause the devi...

Description

A vulnerability in a logging API in Cisco Firepower Management Center (FMC) Software could allow an unauthenticated, remote attacker to cause the device to become unresponsive or trigger an unexpected reload. This vulnerability could also allow an attacker with valid user credentials, but not Administrator privileges, to view a system log file that they would not normally have access to. This vulnerability is due to a lack of rate-limiting of requests that are sent to a specific API that is related to an FMC log. An attacker could exploit this vulnerability by sending a high rate of HTTP requests to the API. A successful exploit could allow the attacker to cause a denial of service (DoS) condition due to the FMC CPU spiking to 100 percent utilization or to the device reloading. CPU utilization would return to normal if the attack traffic was stopped before an unexpected reload was triggered.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

0.67%

47.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Cisco	Secure Firewall Management Center	>= 6.2.3, <= 6.2.3.18
Cisco	Secure Firewall Management Center	>= 6.4.0, <= 6.4.0.16
Cisco	Secure Firewall Management Center	>= 6.6.0, <= 6.6.7.1
Cisco	Secure Firewall Management Center	>= 7.0.0, <= 7.0.5
Cisco	Secure Firewall Management Center	>= 7.1.0, <= 7.1.0.3
Cisco	Secure Firewall Management Center	>= 7.2.0, <= 7.2.3.1
Cisco	Secure Firewall Management Center	>= 7.3.0, <= 7.3.1.1

References

Timeline

Published: Nov 1, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-20155?

A vulnerability in a logging API in Cisco Firepower Management Center (FMC) Software could allow an unauthenticated, remote attacker to cause the device to become unresponsive or trigger an unexpected reload. This vulnerability could also allow an attacker with valid user credentials, but not Administrator privileges, to view a system log file that they would not normally have access to. This vulnerability is due to a lack of rate-limiting of requests that are sent to a specific API that is related to an FMC log. An attacker could exploit this vulnerability by sending a high rate of HTTP requests to the API. A successful exploit could allow the attacker to cause a denial of service (DoS) condition due to the FMC CPU spiking to 100 percent utilization or to the device reloading. CPU utilization would return to normal if the attack traffic was stopped before an unexpected reload was triggered.

How severe is CVE-2023-20155?

CVE-2023-20155 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.67% probability of exploitation in the next 30 days.

How do I fix CVE-2023-20155?

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.