CVE-2022-20943

Severity: medium (CVSS 5.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-11-15 · updated 2026-08-11
Weakness: CWE-244

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.

Affected products

Cisco Cyber Vision: 3.0.0, 3.0.1, 3.0.2, 3.0.3, 3.0.5, 3.0.6 (+14)
Cisco Meraki Mx Security Appliance Firmware: before 16.6.7; from 17.0 before 17.11.1; from 18.0 before 18.1.3 — fixed in 16.6.7, 17.11.1, 18.1.3
Cisco Firepower Threat Defense Software: 7.0.0, 7.0.0.1, 7.0.1, 7.0.1.1

How to fix

Upgrade to a fixed version: Cisco Meraki Mx Security Appliance Firmware 16.6.7, 17.11.1, 18.1.3. Check the vendor advisory for mitigations.

References

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