User Enumeration Vulnerability in ZKTeco ZKBioSecurity 3.0
CVE-2016-20030

9.3CRITICAL

Key Information:

Vendor

Zkteco Inc.

Status
Zkteco ZkbiOSecurity
Vendor
CVE Published:
15 March 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2016-20030?

ZKTeco's ZKBioSecurity 3.0 is susceptible to a user enumeration vulnerability that enables unauthenticated attackers to identify valid usernames. By exploiting the application’s authLoginAction!login.do endpoint, attackers can input partial username strings and analyze the responses from the server. Depending on how the application handles the input, attackers may discern which usernames are valid, potentially leading to further attacks such as credential stuffing or phishing. This vulnerability underscores the importance of implementing strict input validation measures to protect user account information.

Affected Version(s)

ZKTeco ZKBioSecurity 3.0.1.0_R_230

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2016-20030 - Proof of Concept

References

https://www.zeroscience.mk/en/vulnerabilities/ZSL-2016-53...
third-party-advisory
https://exchange.xforce.ibmcloud.com/vulnerabilities/116485
vdb-entry
https://packetstormsecurity.com/files/138573
exploit

CVSS V4

Score:
9.3
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

LiquidWorm as Gjoko Krstic of Zero Science Lab
.