CVE-2016-20031: ZKTeco Inc ZKTeco Zkbiosecurity

Medium severity, CVSS 5.5. EPSS: 0.1% chance of exploitation in the next 30 days.

ZKTeco ZKBioSecurity 3.0 contains a local authorization bypass vulnerability in visLogin.jsp that allows attackers to authenticate without valid credentials by spoofing localhost requests. Attackers can exploit the EnvironmentUtil.getClientIp() method which treats IPv6 loopback address 0:0:0:0:0:0:0:1 as 127.0.0.1 and authenticates using the IP as username with hardcoded password 123456 to access sensitive information and perform unauthorized actions.

Affected products

• ZKTeco Inc ZKTeco Zkbiosecurity: version 3.0.1.0_R_230 only

Published 2026-03-16. Last modified 2026-06-17.