En bref
- CVE-2021-29444 est une vulnérabilité MOYENNE (CVSS 5.9) touchant jose-node-cjs-runtime (jose-node-cjs-runtime project), jose-browser-runtime.
- Probabilité d'exploitation dans les 30 prochains jours (EPSS) : 1.1%, plus élevée que 64.9% des vulnérabilités.
- Correctif : mettre à jour vers 3.11.4 ou plus récent.
Description
Impact
AES_CBC_HMAC_SHA2 Algorithm (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.
NVD description
jose-browser-runtime is an npm package which provides a number of cryptographic functions. In versions prior to 3.11.4 the AES_CBC_HMAC_SHA2 Algorithm (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). 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`.
Autres vulnérabilités de jose-node-cjs-runtime
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