CVE-2025-55279
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedThis 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceZKTeco WL20 devices contain a hard-coded plaintext private key embedded in the firmware binary. An attacker with physical access can extract the firmware image and statically analyze it to recover this private key, enabling decryption of sensitive communications and man-in-the-middle attacks.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Physical
- Complexity
- Low
- Privileges
- None
- Authentication
- X
- User interaction
- None
- Scope
- X
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/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
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Confirm device is ZKTeco WL20Log into the device web interface or check the physical device label to verify the model number is WL20Affected if Device model is ZKTeco WL20 and is running any firmware version
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Obtain current firmware versionAccess device settings via web interface or use serial/SSH connection to retrieve firmware version informationAffected if Firmware version cannot be verified or is older than latest available from vendor
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Extract firmware imageUse manufacturer-provided firmware update file or physically extract flash memory from device to obtain firmware binaryAffected if Firmware image is obtained for analysis
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Search firmware binary for private key patternsUse strings, binwalk, or hex editor to search firmware for key file headers (BEGIN RSA PRIVATE KEY, BEGIN EC PRIVATE KEY, BEGIN PRIVATE KEY), large hexadecimal strings (typically 1024+ bits for RSA), or base64-encoded key patternsAffected if Private key in plaintext or easily decodable format is found embedded in firmware binary
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Verify key is unique per deviceIf a private key is found, compare with keys extracted from other WL20 devices or firmware versions to confirm it is hardcoded (same across multiple units) rather than device-specificAffected if Same private key appears across multiple devices or firmware versions indicating hardcoded implementation
User is affected if device is a ZKTeco WL20 and analysis of its firmware reveals an embedded plaintext private key that is shared across devices.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataContact ZKTeco for patched firmware that removes the hardcoded key and implements proper key management; prioritize updating devices in high-security areas and monitor for indicators of compromise.
- Consultation6.0 h
- Implementation12.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,448.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-55279 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-55279 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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