GHSA-h45p-w933-jxh3
GHSA-h45p-w933-jxh3 is a security vulnerability in @aws-crypto/client-browser. O3 Security confirms whether GHSA-h45p-w933-jxh3 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Improper Verification of Cryptographic Signature in aws-encryption-sdk-javascript
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@aws-crypto/client-browsernpm@aws-crypto/client-nodenpmDescription
Impact
This advisory addresses several LOW severity issues with streaming signed messages and restricting processing of certain types of invalid messages.
This ESDK supports a streaming mode where callers may stream the plaintext of signed messages before the ECDSA signature is validated. In addition to these signatures, the ESDK uses AES-GCM encryption and all plaintext is verified before being released to a caller. There is no impact on the integrity of the ciphertext or decrypted plaintext, however some callers may rely on the the ECDSA signature for non-repudiation. Without validating the ECDSA signature, an actor with trusted KMS permissions to decrypt a message may also be able to encrypt messages. This update introduces a new API for callers who wish to stream only unsigned messages.
For customers who process ESDK messages from untrusted sources, this update also introduces a new configuration to limit the number of Encrypted Data Keys (EDKs) that the ESDK will attempt to process per message. This configuration provides customers with a way to limit the number of AWS KMS Decrypt API calls that the ESDK will make per message. This setting will reject messages with more EDKs than the configured limit.
Finally, this update adds early rejection of invalid messages with certain invalid combinations of algorithm suite and header data.
Patches
Fixed in versions 1.9 and 2.2. We recommend that all users upgrade to address these issues.
Customers leveraging the ESDK’s streaming features have several options to protect signature validation. One is to ensure that client code reads to the end of the stream before using released plaintext. With this release, using the new API for streaming and falling back to the non-streaming decrypt API for signed messages prevents using any plaintext from signed data before the signature is validated. See https://docs.aws.amazon.com/encryption-sdk/latest/developer-guide/about-versions.html#version2.2.x
Users processing ESDK messages from untrusted sources should use the new maximum encrypted data keys parameter. See https://docs.aws.amazon.com/encryption-sdk/latest/developer-guide/about-versions.html#version2.2.x
Workarounds
None
For more information
https://docs.aws.amazon.com/encryption-sdk/latest/developer-guide/concepts.html#digital-sigs
https://docs.aws.amazon.com/encryption-sdk/latest/developer-guide/about-versions.html#version2.2.x
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @aws-crypto/client-browser | all versions | 1.9.0 |
| 📦npm | @aws-crypto/client-browser | ≥ 2.0.0&&< 2.2.0 | 2.2.0 |
| 📦npm | @aws-crypto/client-node | all versions | 1.9.0 |
| 📦npm | @aws-crypto/client-node | ≥ 2.0.0&&< 2.2.0 | 2.2.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @aws-crypto/client-browser. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update @aws-crypto/client-browser to 1.9.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-h45p-w933-jxh3 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-h45p-w933-jxh3 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-h45p-w933-jxh3. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-h45p-w933-jxh3 in your dependencies?
O3 detects GHSA-h45p-w933-jxh3 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.