CVE-2020-28214
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 · uneditedA CWE-760: Use of a One-Way Hash with a Predictable Salt vulnerability exists in Modicon M221 (all references, all versions), that could allow an attacker to pre-compute the hash value using dictionary attack technique such as rainbow tables, effectively disabling the protection that an unpredictable salt would provide.
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 confidenceThe Modicon M221 PLC uses a one-way hash function with a predictable salt for password storage, violating security best practices. Because the salt is predictable rather than cryptographically random per-user, attackers can pre-compute hash values using rainbow tables and perform dictionary attacks to recover passwords, effectively bypassing the intended salt-based protection.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE dataall versionsCVSS 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
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
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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Identify Modicon M221 PLCs on the networkUse network scanning tools (such as Nmap) or PLC discovery tools to identify devices with vendor identifier for Schneider Electric and model identification for M221. Check device documentation or asset inventory for Modicon M221 controllers.Affected if Any Modicon M221 PLC is found on the network
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Check firmware version of identified devicesAccess the PLC through its web interface (if enabled), EcoStruxure Machine Advisor, or Unity Pro/Schneider Electric programming software. Navigate to system information or firmware properties to retrieve the installed version number.Affected if The device is confirmed as a Modicon M221 with any firmware version (all versions are affected)
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Verify web server is enabled on the PLCAttempt to access the PLC web interface by navigating to its IP address via HTTPS. Check if the built-in web server feature is activated in the PLC configuration using the programming software.Affected if Web server access is available and password storage can be inspected
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Inspect password storage mechanismIf administrative access is available, examine the password configuration section in the web interface or export the project file from Unity Pro. Look for how passwords are stored (hashing algorithm and salt generation method).Affected if Password storage uses a predictable salt rather than cryptographically random per-user salts, allowing rainbow table attacks
If Modicon M221 PLCs exist in the environment with any firmware version, they are affected by this vulnerability due to the use of predictable salts in password hashing.
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 dataApply vendor-provided firmware updates when available; if no patch exists, implement compensating controls such as network segmentation, strict access controls, and monitoring to limit exposure to attackers who might exploit this weakness.
- Consultation6.0 h
- Implementation12.0 h
- Testing6.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-28214 — 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-2020-28214 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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- Version or environment caveats, and links to real fixes
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