Vulnerability in Cisco Firepower Threat Defense Software

CVE-2023-20177

A vulnerability in the SSL file policy implementation of Cisco Firepower Threat Defense (FTD) Software that occurs when the SSL/TLS connection is configured with a URL Category and the Snort 3 detection engine could allow an unauthenticated, remote attacker to cause the Snort 3 detection engine to unexpectedly restart. This vulnerability exists because a logic error occurs when a Snort 3 detection engine inspects an SSL/TLS connection that has either a URL Category configured on the SSL file policy or a URL Category configured on an access control policy with TLS server identity discovery enabled. Under specific, time-based constraints, an attacker could exploit this vulnerability by sending a crafted SSL/TLS connection through an affected device. A successful exploit could allow the attacker to trigger an unexpected reload of the Snort 3 detection engine, resulting in either a bypass or denial of service (DoS) condition, depending on device configuration. The Snort 3 detection engine will restart automatically. No manual intervention is required.

EPSS: 0.005 (42.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.0 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:L.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2023-20177?
CVE-2023-20177 is a medium-severity vulnerability in Cisco Firepower Threat Defense Software, classified under CWE-244. CVSS score: 4.0/10. Published 2023-11-01.
How severe is CVE-2023-20177?
Medium severity. CVSS v3 base score is 4.0 out of 10.