CVE-2023-20177

Published Nov 1, 2023 CVSS 3.1 · 4 Medium EPSS < 1% KEV · Not listed

Description

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.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Cisco

Cisco Firepower Threat Defense Software

affected

Version	Status	Constraints
`7.0.0`	affected	—
`7.0.0.1`	affected	—
`7.0.1`	affected	—
`7.0.1.1`	affected	—
`7.0.2`	affected	—
`7.0.2.1`	affected	—
`7.0.3`	affected	—
`7.0.4`	affected	—
`7.0.5`	affected	—
`7.1.0`	affected	—
`7.1.0.1`	affected	—
`7.1.0.2`	affected	—
`7.1.0.3`	affected	—
`7.2.0`	affected	—
`7.2.0.1`	affected	—
`7.2.1`	affected	—
`7.2.2`	affected	—
`7.2.3`	affected	—
`7.3.0`	affected	—
`7.3.1`	affected	—
`7.3.1.1`	affected	—

Configuration 1 [-]

OR	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.0:::::::*
	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.0.1:::::::*
	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.1:::::::*
	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.1.1:::::::*
	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.2:::::::*
	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.2.1:::::::*
	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.3:::::::*
	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.4:::::::*
	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.5:::::::*
	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0:::::::*
	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0.1:::::::*
	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0.2:::::::*
	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0.3:::::::*
	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.0:::::::*
	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.0.1:::::::*
	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.1:::::::*
	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.2:::::::*
	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.3:::::::*
	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.3.0:::::::*
	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.3.1:::::::*
	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.3.1.1:::::::*

No data.

No data available yet.

Remediation

No solution or workaround provided in the CVE record

Tracking

Advisories

Source	ID	Title
EUVD	EUVD-2023-24356	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.

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Changed

Confidentiality Impact None

Integrity Impact None

Availability Impact Low

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.711% probability within 30 days)

Key SSVC decision points have not yet been added.

References

Link	Providers
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sa-ftd-snort3-urldos-OccFQTeX

History

Aug 11, 2026 8:00 PM First appearance in the feed. Affected versions updated. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Cisco secure Firewall Threat Defense
CPEs	cpe:2.3:a:cisco:firepower_threat_defense:7.0.0.1:::::::* cpe:2.3:a:cisco:firepower_threat_defense:7.0.0:::::::* cpe:2.3:a:cisco:firepower_threat_defense:7.0.1.1:::::::* cpe:2.3:a:cisco:firepower_threat_defense:7.0.1:::::::* cpe:2.3:a:cisco:firepower_threat_defense:7.0.2.1:::::::* cpe:2.3:a:cisco:firepower_threat_defense:7.0.2:::::::* cpe:2.3:a:cisco:firepower_threat_defense:7.0.3:::::::* cpe:2.3:a:cisco:firepower_threat_defense:7.0.4:::::::* cpe:2.3:a:cisco:firepower_threat_defense:7.0.5:::::::* cpe:2.3:a:cisco:firepower_threat_defense:7.1.0.1:::::::* cpe:2.3:a:cisco:firepower_threat_defense:7.1.0.2:::::::* cpe:2.3:a:cisco:firepower_threat_defense:7.1.0.3:::::::* cpe:2.3:a:cisco:firepower_threat_defense:7.1.0:::::::* cpe:2.3:a:cisco:firepower_threat_defense:7.2.0.1:::::::* cpe:2.3:a:cisco:firepower_threat_defense:7.2.0:::::::* cpe:2.3:a:cisco:firepower_threat_defense:7.2.1:::::::* cpe:2.3:a:cisco:firepower_threat_defense:7.2.2:::::::* cpe:2.3:a:cisco:firepower_threat_defense:7.2.3:::::::* cpe:2.3:a:cisco:firepower_threat_defense:7.3.0:::::::* cpe:2.3:a:cisco:firepower_threat_defense:7.3.1.1:::::::* cpe:2.3:a:cisco:firepower_threat_defense:7.3.1:::::::*	cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.0.1:::::::* cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.0:::::::* cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.1.1:::::::* cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.1:::::::* cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.2.1:::::::* cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.2:::::::* cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.3:::::::* cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.4:::::::* cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.5:::::::* cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0.1:::::::* cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0.2:::::::* cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0.3:::::::* cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0:::::::* cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.0.1:::::::* cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.0:::::::* cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.1:::::::* cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.2:::::::* cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.3:::::::* cpe:2.3:a:cisco:secure_firewall_threat_defense:7.3.0:::::::* cpe:2.3:a:cisco:secure_firewall_threat_defense:7.3.1.1:::::::* cpe:2.3:a:cisco:secure_firewall_threat_defense:7.3.1:::::::*
Vendors & Products	Cisco firepower Threat Defense	Cisco secure Firewall Threat Defense