CVE intelligence and bounded remediation

CVE-2021-29443 — jose is an npm library providing a number of cryptographic operations

Medium CVSS 5.9

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.

Severity
Medium
CVSS
5.9 (3.1)
Published
2021-04-16
CISA KEV
Not currently listed
Ecosystem
windows/system
Weaknesses
CWE-203

Affected products

  • panva / jose

Showing 1 representative product identities from 3 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Information disclosure and sensitive data exposure

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace sensitive data through responses, errors, logs, metrics, traces, caches, exports, files, backups, and client bundles.
  • Identify affected subjects, tenants, retention windows, access controls, and downstream copies without opening unnecessary sensitive records.
  • Review metadata, timing, status, length, and existence signals as well as direct content disclosure.

Remediate safely

  • Minimize collection and output, apply field-level authorization and redaction at a centralized boundary, and return generic external errors.
  • Remove secrets and sensitive data from logs, artifacts, URLs, caches, and client-side bundles; rotate credentials that may have been exposed.
  • Update the affected component and add synthetic-data tests for response, error, observability, and export paths.

Authoritative sources

Complete CVE record and remediation plan

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