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PatchSiren cyber security CVE debrief

CVE-2016-20030 ZKTeco Inc. CVE debrief

CVE-2016-20030 is a critical user enumeration vulnerability in ZKTeco ZKBioSecurity 3.0. Unauthenticated attackers can discover valid usernames by submitting partial characters via the username parameter to the authLoginAction!login.do script.

Vendor
ZKTeco Inc.
Product
ZKTeco ZKBioSecurity
CVSS
CRITICAL 9.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-03-16
Original CVE updated
2026-06-08
Advisory published
2026-03-16
Advisory updated
2026-06-08

Who should care

Security teams and administrators responsible for ZKTeco ZKBioSecurity 3.0 systems should prioritize patching this vulnerability to prevent potential attacks.

Technical summary

The vulnerability has a CVSS score of 9.3 and is classified as CRITICAL. It allows attackers to send requests to the authLoginAction!login.do script with varying username inputs to enumerate valid user accounts based on application responses.

Defensive priority

High

Recommended defensive actions

  • Apply patches or updates provided by the vendor to fix the user enumeration vulnerability.
  • Implement additional security measures, such as rate limiting and IP blocking, to prevent exploitation attempts.
  • Monitor system logs for suspicious activity related to the authLoginAction!login.do script.

Evidence notes

The CVE record and NVD detail can be found at [cve-org] and [nvd], respectively. Additional information can be found at [ref-4], [ref-5], [ref-6], and [ref-7].

Sources and references

Verified primary and authoritative sources

  • CVE-2016-20030 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2016-20030

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2016-20030 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2016-20030

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.