Multiple Cisco Products Snort SMB2 Detection Engine Policy Bypass and Denial of Service Vulnerabilities

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.

Cisco has released software updates that address these vulnerabilities. There are workarounds that address these vulnerabilities.

This advisory is available at the following link:
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort-smb-3nfhJtr [“https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20191106-wsa-unauth-devreset”]

This advisory is part of the November 2022 release of the Cisco ASA, FTD, and FMC Security Advisory Bundled publication. For a complete list of the advisories and links to them, see Cisco Event Response: November 2022 Semiannual Cisco ASA, FMC, and FTD Software Security Advisory Bundled Publication [“https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-74838”].