A vulnerability in the SNORT detection engine of Cisco Firepower System Software could allow an unauthenticated, remote attacker to bypass a file policy that is configured to block the Server Message Block Version 2 (SMB2) protocol. The vulnerability is due to the incorrect detection of an SMB2 file when the detection is based on the length of the file. An attacker could exploit this vulnerability by sending a crafted SMB2 transfer request through the targeted device. A successful exploit could allow the attacker to bypass filters that are configured to block SMB2 traffic. Cisco Bug IDs: CSCve58398.