CVE-2020-3164

CVE-2020-3164 is a denial-of-service vulnerability affecting the web-based management interface of Cisco Email Security Appliance (ESA), Web Security Appliance (WSA), and Content Security Management Appliance (SMA). An unauthenticated remote attacker can exploit improper validation of HTTP request headers by sending a malformed request, leading to high CPU utilization and degraded performance. Rated as Medium severity (CVSS 5.3), this vulnerability has a network attack vector and low attack complexity, requiring no user interaction. A successful exploit results in a denial of service (availability impact) but does not compromise confidentiality or integrity. Currently, there is no evidence of active exploitation, and no public exploit code (Metasploit, Nuclei, ExploitDB) is available. The vulnerability has received minimal community discussion and media coverage, indicating low public attention.