CVE-2020-15522
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 · uneditedBouncy Castle BC Java before 1.66, BC C# .NET before 1.8.7, BC-FJA before 1.0.1.2, 1.0.2.1, and BC-FNA before 1.0.1.1 have a timing issue within the EC math library that can expose information about the private key when an attacker is able to observe timing information for the generation of multiple deterministic ECDSA signatures.
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 confidenceA timing side-channel vulnerability exists in the Bouncy Castle EC (Elliptic Curve) math library across multiple language variants (Java, C#, FJA, FNA). When generating deterministic ECDSA signatures, the timing of cryptographic operations leaks information about the private key. An attacker with the ability to observe timing data across multiple signature operations can potentially recover or partial-recover the ECDSA private key through statistical analysis of timing variations.
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< 1.8.7< 1.0.1.1< 1.0.1.2>= 1.0.2, < 1.0.2.1< 1.66CVSS 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
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:H/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 Bouncy Castle library presenceSearch project dependencies (Maven pom.xml, NuGet packages.config, Gradle build files) or inspect JAR/DLL assemblies for Bouncy Castle libraries (org.bouncycastle.* for Java, BouncyCastle.* for .NET)Affected if Bouncy Castle library is present in the environment
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Determine installed Bouncy Castle versionFor Java: inspect the bouncycastle JAR file name or check runtime via Security.getProvider("BC").getVersion(). For .NET: check the BouncyCastle.Crypto.dll assembly version or NuGet package version installedAffected if Version is below 1.66 for Java BC, below 1.8.7 for C#, below 1.0.1.1 for FIPS .NET, or below 1.0.1.2/1.0.2.1 for FIPS Java as listed in affected versions
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Verify ECDSA signature generation is in useReview code for use of java.security.Signature, org.bouncycastle.jce.provider.BouncyCastleProvider with ECDSA algorithms (ECDSA, SHA256withECDSA, etc.) or .NET equivalents using Bouncy Castle EC keys and sign operationsAffected if Application performs ECDSA signing operations using Bouncy Castle as the crypto provider
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Confirm deterministic ECDSA is configuredInspect signature algorithm configuration - deterministic ECDSA (RFC 6979) is typically enabled by specifying algorithms like NONEwithECDSA or ECDSA with deterministic nonce generation via Bouncy Castle's ECDSA signer classesAffected if Deterministic ECDSA signature generation is performed, as the timing leak manifests during the nonce generation in signing operations
User is affected if Bouncy Castle library is present with a version in the affected ranges AND the application uses ECDSA signing operations.
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 data1.0.1.11.0.1.21.0.2.1
Upgrade Bouncy Castle libraries to versions that contain the fix: BC Java 1.66+, BC C# .NET 1.8.7+, BC-FJA 1.0.1.2/1.0.2.1/1.0.1.1+, or BC-FNA 1.0.1.1+. If upgrading is not immediately feasible, monitor signature operation timing and consider using constant-time implementations or hardware security modules.
- Consultation3.0 h
- Implementation2.0 h
- Testing6.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-15522 — 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-2020-15522 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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