cisco-sa-sa-ftd-snort3-urldos-OccFQTeX
Cisco Firepower Threat Defense Software SSL/TLS URL Category and Snort 3 Detection Engine Bypass and Denial of Service Vulnerability
Medium · Updated · Cisco
8 products with CSAF evidence
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. See the Details section of this advisory for more information. The Snort 3 detection engine will restart automatically. No manual intervention is required. Cisco has released software updates that address this vulnerability. There are workarounds that address this vulnerability.