Is CVE-2016-20031 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2016-20031 being exploited in the wild.

How severe is CVE-2016-20031?

Medium severity, with a CVSS score of 5.5, published 16 March 2026.

Which products and versions are affected?

Zkteco ZKBioSecurity 3.0.1.0_R_230 and earlier.

Is there a fix for CVE-2016-20031?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2016-20031 attacked?

It is attacked with local access, in a network appliance.

Am I affected by CVE-2016-20031?

Check whether you run Zkteco ZKBioSecurity at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2016-20031: ZKTeco ZKBioSecurity auth bypass in visLogin.jsp

CVE-2016-20031 · Severity: medium · CVSS 5.5 · Published 2026-03-16

ZKTeco ZKBioSecurity is an integrated security platform used for access control, video surveillance, and visitor management. A vulnerability in the visitor login component allows a local user to bypass normal authentication and gain unauthorized access to the system. By exploiting this flaw, an attacker could view sensitive security information or perform unauthorized actions within the management interface.

Technologies: Zkteco ZKBioSecurity. Vendors: Zkteco.

Quick answers

Is CVE-2016-20031 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2016-20031 being exploited in the wild.
How severe is CVE-2016-20031?: Medium severity, with a CVSS score of 5.5, published 16 March 2026.
Which products and versions are affected?: Zkteco ZKBioSecurity 3.0.1.0_R_230 and earlier.
Is there a fix for CVE-2016-20031?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2016-20031 attacked?: It is attacked with local access, in a network appliance.
Am I affected by CVE-2016-20031?: Check whether you run Zkteco ZKBioSecurity at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A local authorization bypass exists in ZKTeco ZKBioSecurity 3.0 within the 'visLogin.jsp' component. The vulnerability stems from the 'EnvironmentUtil.getClientIp()' method, which incorrectly handles the IPv6 loopback address (0:0:0:0:0:0:0:1) by treating it as the IPv4 localhost (127.0.0.1). The application then automatically attempts to authenticate using this IP address as the username with a hardcoded password of '123456'. An attacker with local access can exploit this logic to bypass standard authentication mechanisms and gain access to the web-based security platform. This issue affects version 3.0.1.0_R_230 and potentially earlier versions.

Affected products

ZKTeco ZKBioSecurity 3.0 3.0.1.0_R_230 and earlier

Timeline

2016-07-18: disclosed: Vulnerability discovered by Zero Science Lab
2016-08-31: advisory: Exploit-DB entry published
2016-09-01: advisory: CXSecurity advisory published
2026-03-16: other: CVE-2016-20031 assigned/published in NVD

References

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