9.8
CRITICAL CVSS 3.1
CVE-2016-20030
ZKTeco ZKBioSecurity 3.0 User Enumeration via authLoginAction
Description

ZKTeco ZKBioSecurity 3.0 contains a user enumeration vulnerability that allows unauthenticated attackers to discover valid usernames by submitting partial characters via the username parameter. Attackers can send requests to the authLoginAction!login.do script with varying username inputs to enumerate valid user accounts based on application responses.

INFO

Published Date :

March 16, 2026, 2:17 p.m.

Last Modified :

March 16, 2026, 2:53 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2016-20030 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 CRITICAL 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 CRITICAL [email protected]
CVSS 4.0 CRITICAL 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 CRITICAL [email protected]
Solution
Disable user enumeration or implement rate limiting to prevent username discovery.
  • Disable user enumeration features.
  • Implement rate limiting on login attempts.
  • Update the software to the latest version.
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2016-20030 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2016-20030 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2016-20030 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2016-20030 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Mar. 16, 2026

    Action Type Old Value New Value
    Added Description ZKTeco ZKBioSecurity 3.0 contains a user enumeration vulnerability that allows unauthenticated attackers to discover valid usernames by submitting partial characters via the username parameter. Attackers can send requests to the authLoginAction!login.do script with varying username inputs to enumerate valid user accounts based on application responses.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-551
    Added Reference https://exchange.xforce.ibmcloud.com/vulnerabilities/116485
    Added Reference https://packetstormsecurity.com/files/138573
    Added Reference https://www.vulncheck.com/advisories/zkteco-zkbiosecurity-user-enumeration-via-authloginaction
    Added Reference https://www.zeroscience.mk/en/vulnerabilities/ZSL-2016-5366.php
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.