Security readout for executives and security teams
Plain-English summary
ZKTeco ZKBioSecurity 3.0.1.0_R_230 includes hardcoded Tomcat manager credentials. An attacker who can reach that service can log in without legitimate access and run code on the server. The source bundle describes execution with SYSTEM privileges, making compromise potentially complete.
Executive priority
Prioritize within the current emergency patch or exposure-reduction cycle if this product is deployed. A successful attack could give full server control, potentially affecting physical access, identity, or attendance systems tied to ZKBioSecurity.
Technical view
CVE-2016-20026 is CWE-798 in ZKTeco ZKBioSecurity 3.0.1.0_R_230. Hardcoded credentials in tomcat-users.xml expose the bundled Apache Tomcat manager application. Remote unauthenticated attackers can authenticate and upload a malicious WAR/JSP application, leading to arbitrary code execution as SYSTEM. CVSS 3.1 is 9.8.
Likely exposure
Risk is highest where ZKBioSecurity 3.0.1.0_R_230 or its bundled Tomcat manager is reachable from untrusted networks. Internet-facing deployments are especially exposed. Organizations using ZKTeco biometric/access-control systems should verify product version and management interface exposure.
Exploitation context
The bundle cites public exploit references from Packet Storm and Exploit-DB, so attacker knowledge is publicly available. CISA KEV status is false in the provided data, and no cited source confirms active exploitation. Treat reachable instances as urgent because exploitation requires no prior account.
Researcher notes
Evidence supports hardcoded credential RCE in the bundled Tomcat manager for version 3.0.1.0_R_230. Public exploit references exist, but supplied sources do not establish active exploitation or a vendor patch. Validate exposure carefully and avoid relying on CVE publication date alone; the advisory history is older.
Mitigation direction
- Inventory ZKTeco ZKBioSecurity deployments and confirm exact versions.
- Remove internet exposure for the bundled Tomcat manager interface.
- Restrict access to management services to trusted administrative networks only.
- Check ZKTeco guidance for fixed versions or supported remediation.
- If feasible, disable unused Tomcat manager functionality.
- Monitor servers for unexpected web applications or administrative logins.
Validation and detection
- Confirm whether ZKBioSecurity 3.0.1.0_R_230 is present.
- Identify whether the bundled Tomcat service is running.
- Verify Tomcat manager is not reachable from untrusted networks.
- Review Tomcat configuration for bundled hardcoded manager users.
- Inspect deployed web applications for unauthorized additions.
- Review host logs for suspicious management access or process activity.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-798: Credential and account abuse lookup
Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2016-20026 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- Zero Science Lab DisclosureCVE reference · third-party-advisory
- CXSecurityCVE reference · third-party-advisory
- IBM X-Force ExchangeCVE reference · vdb-entry
- Packet Storm SecurityCVE reference · exploit
- ReferenceCVE reference · exploit
- VulnCheck Advisory: ZKTeco ZKBioSecurity 3.0 Hardcoded Credentials Remote Code ExecutionCVE reference · third-party-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Use of Hard-coded Credentials
Use of Hard-coded Credentials represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.