CVE-2021-41106
File reference keys leads to incorrect hashes on HMAC algorithms
Impact
### 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: ```diff -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'); ```
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| composer | lcobucci/jwt | >= 3.4.0, < 3.4.6 | 3.4.6 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Lcobucci | Jwt | from 3.4.0 before 3.4.6 from 4.0.0 before 4.0.4 from 4.1.0 before 4.1.5 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/lcobucci/jwt/commit/8175de5b841fbe3fd97d2d49b3fc15c4ecb39a73
- https://github.com/lcobucci/jwt/commit/c45bb8b961a8e742d8f6b88ef5ff1bd5cca5d01c
- https://github.com/lcobucci/jwt/security/advisories/GHSA-7322-jrq4-x5hf
- https://github.com/advisories/GHSA-7322-jrq4-x5hf
- https://nvd.nist.gov/vuln/detail/CVE-2021-41106
- https://github.com/FriendsOfPHP/security-advisories/blob/master/lcobucci/jwt/CVE-2021-41106.yaml