CVE-2022-20943: Multiple vulnerabilities in the Server Message Block Version 2 (SMB2) processor of the Snort detection engine on multiple Cisco products could allow a...

Description

Multiple vulnerabilities in the Server Message Block Version 2 (SMB2) processor of the Snort detection engine on multiple Cisco products could allow an unauthenticated, remote attacker to bypass the configured policies or cause a denial of service (DoS) condition on an affected device. These vulnerabilities are due to improper management of system resources when the Snort detection engine is processing SMB2 traffic. An attacker could exploit these vulnerabilities by sending a high rate of certain types of SMB2 packets through an affected device. A successful exploit could allow the attacker to trigger a reload of the Snort process, resulting in a DoS condition. Note: When the snort preserve-connection option is enabled for the Snort detection engine, a successful exploit could also allow the attacker to bypass the configured policies and deliver a malicious payload to the protected network. The snort preserve-connection setting is enabled by default. See the Details ["#details"] section of this advisory for more information. Note: Only products that have Snort 3 configured are affected. Products that are configured with Snort 2 are not affected.

Metrics

CVSS 3.1

5.8/10

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

EPSS Probability

0.89%

54.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-244

Affected Software

Vendor	Product	Versions
Cisco	Firepower Threat Defense	7.0.0
Cisco	Firepower Threat Defense	7.0.0.1
Cisco	Firepower Threat Defense	7.0.1
Cisco	Firepower Threat Defense	7.0.1.1
Cisco	Cyber Vision	3.0.0
Cisco	Cyber Vision	3.0.1
Cisco	Cyber Vision	3.0.2
Cisco	Cyber Vision	3.0.3
Cisco	Cyber Vision	3.0.5
Cisco	Cyber Vision	3.0.6
Cisco	Cyber Vision	3.1.0
Cisco	Cyber Vision	3.1.1
Cisco	Cyber Vision	3.1.2
Cisco	Cyber Vision	3.2.0
Cisco	Cyber Vision	3.2.1
Cisco	Cyber Vision	3.2.2
Cisco	Cyber Vision	3.2.3
Cisco	Cyber Vision	3.2.4
Cisco	Cyber Vision	4.0.0
Cisco	Cyber Vision	4.0.1
Cisco	Cyber Vision	4.0.2
Cisco	Cyber Vision	4.0.3
Cisco	Cyber Vision	4.1.0
Cisco	Cyber Vision	4.1.1
Cisco	Meraki Mx Security Appliance Firmware	< 16.6.7
Cisco	Meraki Mx Security Appliance Firmware	>= 17.0, < 17.11.1
Cisco	Meraki Mx Security Appliance Firmware	>= 18.0, < 18.1.3

References

Timeline

Published: Nov 15, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2022-20943?

Multiple vulnerabilities in the Server Message Block Version 2 (SMB2) processor of the Snort detection engine on multiple Cisco products could allow an unauthenticated, remote attacker to bypass the configured policies or cause a denial of service (DoS) condition on an affected device. These vulnerabilities are due to improper management of system resources when the Snort detection engine is processing SMB2 traffic. An attacker could exploit these vulnerabilities by sending a high rate of certain types of SMB2 packets through an affected device. A successful exploit could allow the attacker to trigger a reload of the Snort process, resulting in a DoS condition. Note: When the snort preserve-connection option is enabled for the Snort detection engine, a successful exploit could also allow the attacker to bypass the configured policies and deliver a malicious payload to the protected network. The snort preserve-connection setting is enabled by default. See the Details ["#details"] section of this advisory for more information. Note: Only products that have Snort 3 configured are affected. Products that are configured with Snort 2 are not affected.

How severe is CVE-2022-20943?

CVE-2022-20943 has a CVSS score of 5.8/10 (MEDIUM severity). The EPSS model estimates a 0.89% probability of exploitation in the next 30 days.

How do I fix CVE-2022-20943?

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.