CVE-2021-29444 Padding Oracle Attack due to Observable Timing Discrepancy in jose-browser-runtime

What is CVE-2021-29444?

CVE-2021-29444 is a medium-severity vulnerability in panva jose, published on 16 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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`.

Weakness: CWE-203

Which versions are affected by CVE-2021-29444?

2 open source packages ship an affected version, including jose-browser-runtime. It affects 1 product.

Products include Jose-Node-Cjs-Runtime Project Jose-Node-Cjs-Runtime.

How do I fix CVE-2021-29444?

Upgrade jose-browser-runtime to 3.11.4 or later.

Is CVE-2021-29444 being exploited?

There is no known exploitation of CVE-2021-29444 in the wild and no public exploit code.

Other vulnerabilities in panva jose

• CVE-2021-29445 Padding Oracle Attack due to Observable Timing Discrepancy in jose-node-esm-runtime Medium 5.9
• CVE-2021-29446 Padding Oracle Attack due to Observable Timing Discrepancy in jose-node-cjs-runtime Medium 5.9

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-94hh-pjjg-rwmr.