CVE-2023-22915

A buffer overflow vulnerability in the “fbwifi_forward.cgi” CGI program of Zyxel USG FLEX series firmware versions 4.50 through 5.35, USG FLEX 50(W) firmware versions 4.30 through 5.35, USG20(W)-VPN firmware versions 4.30 through 5.35, and VPN series firmware versions 4.30 through 5.35, which could allow a remote unauthenticated attacker to cause DoS conditions by sending a crafted HTTP request if the Facebook WiFi function were enabled on an affected device.

• zyxel usg flex 100 firmware (>= 4.50 <= 5.35) • zyxel usg flex 100w firmware (>= 4.50 <= 5.35) • zyxel usg flex 200 firmware (>= 4.50 <= 5.35) • zyxel usg flex 50 firmware (>= 4.50 <= 5.35) • zyxel usg flex 50w firmware (>= 4.30 <= 5.35) • zyxel usg flex 500 firmware (>= 4.50 <= 5.35) • zyxel usg flex 700 firmware (>= 4.50 <= 5.35) • zyxel vpn100 firmware (>= 4.50 <= 5.35) • zyxel vpn1000 firmware (>= 4.50 <= 5.35) • zyxel vpn300 firmware (>= 4.50 <= 5.35) • zyxel vpn50 firmware (>= 4.50 <= 5.35) • zyxel usg 20w-vpn firmware (>= 4.30 <= 5.35)