CVE-2021-29444

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`.

• CVE ID
• CVE-2021-29444

• Assigner
• security-advisories@github.com

• Vulnerability Status
• Analyzed

• Published Version
• 2021-04-16T22:15:13

• Last Modified Date
• 2023-03-21T13:18:38

• Version
• 2.0

• Vector String
• AV:N/AC:M/Au:N/C:P/I:N/A:N

• Access Vector
• NETWORK

• Access Compatibility
• MEDIUM

• Authentication
• NONE

• Confidentiality Impact
• PARTIAL

• Integrity Impact
• NONE

• Availability Impact
• NONE

• Base Score
• 4.3

• Severity
• MEDIUM

• Exploitability Score
• 8.6

• Impact Score
• 2.9

• Version
• 3.1

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

• Attack Vector
• NETWORK

• Attack Compatibility
• HIGH

• Privileges Required
• NONE

• User Interaction
• NONE

• Scope
• UNCHANGED

• Confidentiality Impact
• HIGH

• Availability Impact
• NONE

• Base Score
• 5.9

• Base Severity
• MEDIUM

• Exploitability Score
• 2.2

• Impact Score
• 3.6