CVE-2021-41106: File reference keys leads to incorrect hashes on HMAC algorithms

Description Impact Users of HMAC-based algorithms (HS256, HS384, and HS512) combined with Lcobucci\JWT\Signer\Key\LocalFileReference as key are having their tokens issued/validated using the file path as hashing key - instead of the contents. The HMAC hashing functions take any string as input and, since users can issue and validate tokens, people are lead to believe that everything works properly. Patches All versions have been patched to always load the file contents, deprecated the Lcobucci\JWT\Signer\Key\LocalFileReference, and suggest Lcobucci\JWT\Signer\Key\InMemory as the alternative. Workarounds Use Lcobucci\JWT\Signer\Key\InMemory instead of Lcobucci\JWT\Signer\Key\LocalFileReference to create the instances of your keys: -use Lcobucci\JWT\Signer\Key\LocalFileReference; +use Lcobucci\JWT\Signer\Key\InMemory; -$key = LocalFileReference::file(DIR . ‘/public-key.pem’); +$key = InMemory::file(DIR . ‘/public-key.pem’); References OpenSSL file reference format HMAC hashing Fix for 3.4: c45bb8b Fix for 4.x: 8175de5 For more information If you have any questions or comments about this advisory: Open an issue in lcobucci/jwt Email us at [email protected]