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MEDIUM5.9

GHSA-4v4g-726h-xvfv

Padding Oracle Attack due to Observable Timing Discrepancy in jose-node-esm-runtime

Quick fix

GHSA-4v4g-726h-xvfv — jose-node-esm-runtime: upgrade to the fixed version with the command below.

npm install jose-node-esm-runtime@3.11.4

Details

### Impact

[AES_CBC_HMAC_SHA2 Algorithm](https://tools.ietf.org/html/rfc7518#section-5.2) (A128CBC-HS256, A192CBC-HS384, A256CBC-HS512) decryption would always execute both HMAC tag verification and CBC decryption, if either failed `JWEDecryptionFailed` would be thrown. But a possibly observable difference in timing when padding error would occur while decrypting the ciphertext makes a padding oracle and an adversary might be able to make use of that oracle to decrypt data without knowing the decryption key by issuing on average 128*b calls to the padding oracle (where b is the number of bytes in the ciphertext block).

### Patches

A patch was released which ensures the HMAC tag is verified before performing CBC decryption. The fixed versions are `>=3.11.4`.

Users should upgrade to `^3.11.4`.

### Credits Thanks to Morgan Brown of Microsoft for bringing this up and Eva Sarafianou (@esarafianou) for helping to score this advisory.

Are you affected?

Enter the version of the package you're using.

Affected packages

npm/jose-node-esm-runtime
Introduced in: 0Fixed in: 3.11.4
Fixnpm install jose-node-esm-runtime@3.11.4

References