CVE-2025-55279: ZKTeco Co WL20 Biometric Attendance System · Use of Hard-coded Credentials
Affects ZKTeco Co WL20 Biometric Attendance SystemSource CVE Database V5
Not known to be exploited · CVSS 6.9 Medium.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 13 Aug 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
AI-suggested
European organizations should immediately inventory all ZKTeco WL20 devices and verify firmware versions. Until a vendor patch is available, physical security must be enhanced to prevent unauthorized access to the devices, including secure mounting, tamper-evident seals, and restricted access areas. Firmware extraction should be deterred by deploying devices in controlled environments with surveillance. Network segmentation should isolate attendance systems from critical IT infrastructure to limit lateral movement in case of compromise. Organizations should monitor network traffic for anomalies indicative of MitM attacks or unauthorized decryption attempts. Where possible, consider replacing affected devices with models that do not contain hard-coded credentials or that have received security updates. Additionally, organizations should engage with ZKTeco for timelines on patch releases and apply updates promptly once available. Employee awareness programs should highlight the risks of physical tampering and encourage reporting of suspicious activity.
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.