CVE-2023-20031

What it is

A vulnerability in the SSL/TLS certificate handling of Snort 3 Detection Engine integration with Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort 3 detection engine to restart. This vulnerability is due to a logic error that occurs when an SSL/TLS certificate that is under load is accessed when it is initiating an SSL connection. Under specific, time-based constraints, an attacker could exploit this vulnerability by sending a high rate of SSL/TLS connection requests to be inspected by the Snort 3 detection engine on an affected device. A successful exploit could allow the attacker to cause the Snort 3 detection engine to reload, resulting in either a bypass or a denial of service (DoS) condition, depending on device configuration. The Snort detection engine will restart automatically. No manual intervention is required.

At a glance

Exploitability

Can be exploited over the network without logging in. Limited direct impact.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2023-11-01 18:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-08-11 19:33 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.4% in the next 30 days (EPSS).
• Severity: 4.0 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2023-11-01 18:15 UTC

Last modified

2026-08-11 19:33 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-244

Record status

Modified

Affected

• Cisco Secure Firewall Threat Defense 6.7.0
• Cisco Secure Firewall Threat Defense 6.7.0.1
• Cisco Secure Firewall Threat Defense 6.7.0.2
• Cisco Secure Firewall Threat Defense 6.7.0.3
• Cisco Secure Firewall Threat Defense 7.0.0
• Cisco Secure Firewall Threat Defense 7.0.0.1
• Cisco Secure Firewall Threat Defense 7.0.1
• Cisco Secure Firewall Threat Defense 7.0.1.1

Attack profile CVSS 3.1 · 4.0

Attack vector

Network

Complexity

High

Privileges needed

None

User interaction

None

Scope

Changed

Confidentiality

None

Integrity

Low

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2023-20031.md and follow it. Check whether this project is affected by CVE-2023-20031. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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