CVE-2017-3793

CVE-2017-3793 describes a denial-of-service (DoS) vulnerability in the TCP normalizer of Cisco Adaptive Security Appliance (ASA) Software (versions 8.0-8.7 and 9.0-9.6) and Cisco Firepower Threat Defense (FTD) Software. An unauthenticated, remote attacker can exploit this by sending a high volume of unique TCP connections with out-of-order segments, exhausting the global out-of-order TCP queue. This leads to the dropping of all further incoming traffic on all interfaces, causing a DoS condition. The vulnerability has a CVSSv3 score of 4.0 (Medium), indicating a network attack vector with high attack complexity and low impact on availability. There is no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage.