Quick answers
- Is CVE-2016-20026 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2016-20026 being exploited in the wild.
- How severe is CVE-2016-20026?
- Critical severity, with a CVSS score of 9.8, published 16 March 2026.
- Which products and versions are affected?
- Zkteco ZKBioSecurity <= 3.0.1.0_R_230.
- Is there a fix for CVE-2016-20026?
- 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-2016-20026 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2016-20026?
- 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
ZKTeco ZKBioSecurity (up to version 3.0.1.0_R_230) bundles an Apache Tomcat server (version 7.0.56) with a pre-configured 'manager' application. The configuration file 'tomcat-users.xml' contains hardcoded credentials (username: 'zkteco', password: 'zkt123') with administrative roles including 'manager-gui' and 'manager-script'. An unauthenticated remote attacker can use these credentials to access the Tomcat Manager interface and deploy a malicious WAR archive containing a JSP webshell. Because the service typically runs with high privileges on Windows installations, this results in arbitrary code execution as 'nt authority\system'.
Affected products
- ZKTeco ZKBioSecurity <= 3.0.1.0_R_230
Timeline
- 2016-07-18: disclosed: Vulnerability discovered by Zero Science Lab
- 2016-08-31: advisory: Public advisory and exploit released by Zero Science Lab and Exploit-DB
- 2026-03-16: advisory: CVE-2016-20026 published to NVD
References
- https://cxsecurity.com/issue/WLB-2016080266
- https://exchange.xforce.ibmcloud.com/vulnerabilities/116484
- https://packetstormsecurity.com/files/138567
- https://www.exploit-db.com/exploits/40324/
- https://www.vulncheck.com/advisories/zkteco-zkbiosecurity-hardcoded-credentials-remote-code-execution
- https://www.zeroscience.mk/en/vulnerabilities/ZSL-2016-5362.php