CVE-2021-30246
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 the jsrsasign package through 10.1.13 for Node.js, some invalid RSA PKCS#1 v1.5 signatures are mistakenly recognized to be valid. NOTE: there is no known practical attack.
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 confidenceThe jsrsasign library incorrectly validates RSA PKCS#1 v1.5 signatures, causing certain invalid signatures to be accepted as valid. This signature validation flaw could allow attackers to forge cryptographic signatures for tokens, certificates, or other data protected by this library.
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<= 10.1.13CVSS 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
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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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Locate jsrsasign library in your projectSearch your codebase for 'jsrsasign', 'jsrsasign.js', or 'require("jsrsasign")' / 'import * as jsrsasign' patterns. Check package.json dependencies, node_modules, or CDN imports.Affected if jsrsasign is found in your project dependencies or code
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Identify the installed version of jsrsasignCheck your package.json, package-lock.json, or the version field in the jsrsasign library file itself. Compare the version number to 10.1.13.Affected if The installed version is 10.1.13 or lower
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Determine if RSA PKCS#1 v1.5 signature verification is in useSearch your codebase for calls to signature verification methods such as 'verifyRSASignature', 'KJUR.crypto.Signature', or 'RSAVERIFY' that use 'PKCS1v15' as the padding scheme.Affected if Your code performs RSA PKCS#1 v1.5 signature verification using jsrsasign
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Check for vulnerable signature verification patternsInspect code that uses KJUR.crypto.Signature with algorithm 'SHA256withRSA' or similar RSA algorithms, as these rely on the flawed PKCS#1 v1.5 validation.Affected if Your application verifies RSA signatures using jsrsasign with PKCS#1 v1.5 padding
You are affected if jsrsasign version 10.1.13 or lower is installed AND your code uses it to verify RSA PKCS#1 v1.5 signatures.
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 jsrsasign to a version beyond 10.1.13 that contains the signature validation fix, and audit all code paths relying on this library for signature verification.
- Consultation4.0 h
- Implementation2.0 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 $4,928.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-30246 — 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-2021-30246 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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