CVE-2024-21643
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 · uneditedIdentityModel Extensions for .NET provide assemblies for web developers that wish to use federated identity providers for establishing the caller's identity. Anyone leveraging the `SignedHttpRequest`protocol or the `SignedHttpRequestValidator`is vulnerable. Microsoft.IdentityModel trusts the `jku`claim by default for the `SignedHttpRequest`protocol. This raises the possibility to make any remote or local `HTTP GET` request. The vulnerability has been fixed in Microsoft.IdentityModel.Protocols.SignedHttpRequest. Users should update all their Microsoft.IdentityModel versions to 7.1.2 (for 7x) or higher, 6.34.0 (for 6x) or higher.
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 confidenceMicrosoft.IdentityModel's SignedHttpRequest implementation trusts the jku (JSON Key Set URL) claim by default, allowing an attacker to make arbitrary HTTP GET requests to any remote or local URL (SSRF). This affects applications using SignedHttpRequest or SignedHttpRequestValidator.
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< 6.34.0>= 7.0.0, < 7.1.2CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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 Microsoft.IdentityModel versionInspect the installed Microsoft.IdentityModel.dll version or NuGet package reference in your project (.csproj, packages.config, or the DLL properties in the bin folder). Compare this version against the affected ranges: < 6.34.0 or >= 7.0.0 but < 7.1.2.Affected if The installed version is lower than 6.34.0 (for 6.x releases) or between 7.0.0 and 7.1.1 inclusive (for 7.x releases).
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Identify SignedHttpRequest usageSearch your codebase for any references to 'SignedHttpRequest' or 'SignedHttpRequestValidator' classes, including in authorization handlers, middleware, or validation pipelines. Check all projects that reference Microsoft.IdentityModel.Affected if Your code uses SignedHttpRequest or SignedHttpRequestValidator classes for token validation.
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Inspect jku claim handlingReview the code paths where SignedHttpRequest validation occurs. Look for any custom validation logic that explicitly validates or restricts the 'jku' header/claim before the token is accepted. Check if the SignedHttpRequestProtocolValidationContext is used with any custom jku validation.Affected if No custom validation exists for the jku claim, and the default Microsoft.IdentityModel behavior (which trusts jku) is being used.
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Check runtime dependenciesReview your application's dependency tree (via NuGet, dotnet list package, or a dependency analyzer) to confirm the exact Microsoft.IdentityModel version resolved at runtime matches what you expect. Also verify no binding redirects are overriding the expected version.Affected if A vulnerable version of Microsoft.IdentityModel is loaded at runtime despite a seemingly patched reference.
You are affected if your application uses SignedHttpRequest or SignedHttpRequestValidator with a Microsoft.IdentityModel version below 6.34.0 or between 7.0.0 and 7.1.1, and you rely on the default jku claim handling without custom validation.
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.
dbcve · scoped6.34.07.1.2
Upgrade Microsoft.IdentityModel to version 7.1.2 or higher for 7.x releases, or 6.34.0 or higher for 6.x releases. Review all code paths using SignedHttpRequest to ensure the fix is properly applied and test for compatibility.
6.34.0 (6.x line) or 7.1.2 (7.x line) or higher
- Identify all Microsoft.IdentityModel packages in the project that use SignedHttpRequest functionality (e.g., Microsoft.IdentityModel.Protocols.SignedHttpRequest, Microsoft.IdentityModel.Tokens)
- For projects on the 6.x line: Update package references to version 6.34.0 or higher (e.g., <PackageReference Include="Microsoft.IdentityModel.Protocols.SignedHttpRequest" Version="6.34.0" />)
- For projects on the 7.x line: Update package references to version 7.1.2 or higher (e.g., <PackageReference Include="Microsoft.IdentityModel.Protocols.SignedHttpRequest" Version="7.1.2" />)
- Restore NuGet packages to download the updated versions
- Rebuild the solution to verify compilation succeeds
- Run existing tests to verify the upgrade does not break functionality
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
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- Testing3.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2024-21643 — 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-2024-21643 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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