CVE Tools

CVE-2021-29445

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

No known exploitation. EPSS puts it in the 63rd percentile. A vendor fix is available.

Published Updated Sources: CVE.org, NVD, GitHub

What to do

The vendor has published a fix. Version details are below where the sources state them.

What it is

From the CVE record

jose-node-esm-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`.

In plain language

No plain-language summary for this CVE yet.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS63rd
CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

No public exploit or proof of concept found in the sources we track.

EPSS

1.1% chance of exploitation activity in the next 30 days, which ranks it in the 63rd percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

5 events over 1315 days, from the signal feeds we watch.

  1. Patch availablerecord updated
  2. Publishedweakness classified, att&ck mapped

Affected products

Technical detail

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Scored 5.9 by NVD.

How it is reached

  • Attack Vector NetworkExploitable remotely over the network without any special conditions
  • Attack Complexity HighRequires specific conditions like a race condition or non-default configuration
  • Privileges Required NoneNo authentication required — anyone can exploit this
  • User Interaction NoneNo user interaction needed — fully automated exploitation

Scope

  • Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

  • Confidentiality HighTotal information disclosure — all data in the component is compromised
  • Integrity NoneNo integrity impact
  • Availability NoneNo availability impact

Weaknesses

ATT&CK techniques

Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.

Sources

Watch the software you run.

My Stack ranks new CVEs for your products by real-world exploitation, so the next serious one reaches you without reading every advisory.

We'll flag the next CVE, public exploit or patch for Jose-node-cjs-runtime, not every advisory.

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