CVE-2020-4205
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 · uneditedIBM DataPower Gateway 2018.4.1.0 through 2018.4.1.8 could allow an authenticated user to bypass security restrictions, and continue to access the server even after authentication certificates have been revolked. IBM X-Force ID: 174961.
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 confidenceIBM DataPower Gateway versions 2018.4.1.0 through 2018.4.1.8 contain a flaw in certificate revocation checking where an authenticated user whose certificate has been revoked can still access the server. The gateway fails to properly validate certificate revocation status (likely via CRL or OCSP), allowing continued access after revocation.
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>= 2018.4.1.0, <= 2018.4.1.8CVSS 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
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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Check IBM DataPower Gateway versionAccess the DataPower web GUI, go to Status > System Overview, or use the CLI command 'show version' to retrieve the installed firmware version.Affected if The installed version is 2018.4.1.0 through 2018.4.1.8 inclusive.
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Verify client certificate authentication is enabledIn the web GUI, navigate to Settings > Crypto Tools > SSL Proxy Profile or examine the SSL/TLS configuration for any profile that requires client certificate authentication (often set as 'Required' or 'Optional' with client auth enabled).Affected if SSL/TLS profiles are configured to require or accept client certificates for authentication.
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Confirm CRL or OCSP revocation checking configurationReview the CRL Distribution Point (CRL DP) or OCSP settings in the Crypto Configuration. In the web GUI, go to Settings > Crypto Tools > CRL Configuration or OCSP Configuration to see if revocation checking is defined.Affected if CRL or OCSP revocation checking is configured but the version is vulnerable (2018.4.1.0-2018.4.1.8).
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Identify active revoked certificatesReview the Certificate Revocation List (CRL) or check the OCSP responder for any certificates that have been revoked but may still be in use. Use the CLI command 'show ssl proxy profile' to list profiles and their revocation settings.Affected if There are revoked certificates in the CRL/OCSP that are still being accepted due to the validation failure.
The environment is affected if the DataPower Gateway version is between 2018.4.1.0 and 2018.4.1.8 and client certificate authentication with CRL or OCSP revocation checking is in use.
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 dataUpgrade IBM DataPower Gateway to version 2018.4.1.9 or later, which contains the fix for proper certificate revocation validation.
- Consultation4.0 h
- Implementation6.0 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 $6,080.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-4205 — 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-2020-4205 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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