CVE-2021-20997
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 · uneditedIn multiple managed switches by WAGO in different versions it is possible to read out the password hashes of all Web-based Management users.
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 · high confidenceThis vulnerability in WAGO managed switches allows unauthenticated attackers to read password hashes for all Web-based Management (WBM) users. The exposure of cryptographic password hashes enables offline brute-force attacks to recover plaintext passwords, potentially granting full administrative access to the switch management interface.
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 data<= 1.2.3.s0<= 1.1.7.s0<= 1.1.6.s0<= 1.0.4.s0<= 1.0.4.s0CVSS 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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/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 the device modelAccess the device management interface or check the physical device label to confirm it is a WAGO managed switch from the 0852 series (0852 0303, 0852 1305, 0852 1505, or their /000 001 variants)Affected if The device is not a WAGO 0852 series switch
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Check the firmware versionAccess the switch CLI or WBM interface and retrieve the firmware version. For 0852 0303, compare against <= 1.2.3.s0. For 0852 1305, compare against <= 1.1.7.s0. For 0852 1505, compare against <= 1.1.6.s0. For /000 001 variants, compare against <= 1.0.4.s0Affected if The installed firmware version falls within or below the specified version ranges for your model
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Verify WBM is enabledCheck the switch configuration to determine if Web-based Management (HTTP/HTTPS) interface is enabled and accessible over the networkAffected if WBM is enabled and reachable from a network where unauthenticated attackers could connect
You are affected if you have a WAGO 0852 series switch running a firmware version at or below the specified thresholds with WBM interface enabled and network-accessible
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 firmware patches when available. If patches are unavailable, implement network segmentation to restrict management interface access, disable remote management if feasible, and enforce strong password policies to mitigate dictionary attack success.
- Consultation8.0 h
- Implementation16.0 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 $10,240.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-20997 — 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-2021-20997 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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