CVE-2021-29443

Padding Oracle Attack due to Observable Timing Discrepancy in jose

State
Published
Severity
5.9 Medium
Published
Apr 16, 2021
Updated
Aug 3, 2024
Reserved
Mar 30, 2021

Read the record on cve.org

Description

jose is an npm library providing a number of cryptographic operations. In vulnerable versions 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. 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). All major release versions have had a patch released which ensures the HMAC tag is verified before performing CBC decryption. The fixed versions are `^1.28.1 || ^2.0.5 || >=3.11.4`. Users should upgrade their v1.x dependency to ^1.28.1, their v2.x dependency to ^2.0.5, and their v3.x dependency to ^3.11.4. Thanks to Jason from Microsoft Vulnerability Research (MSVR) for bringing this up and Eva Sarafianou (@esarafianou) for helping to score this advisory.

Scores

CVSSScoreVectorSource
3.15.9 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:NGitHub_M

Weaknesses

  • CWE-203 {"CWE-203":"Observable Discrepancy"}

Affected Products

ProductVersions
josepanva
  • < 1.28.1Affected
  • >= 2.0.0, < 2.0.5Affected
  • >= 3.0.0, < 3.11.4Affected

References

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