File reference keys leads to incorrect hashes on HMAC algorithms
The advisory, in context
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');
Affected packages
Start with the recorded fix for your release branch. Check your installed version and test compatibility before upgrading. Fixing this advisory does not rule out other vulnerabilities in the release.
From 3.4.0 before 3.4.6
Fixed in 3.4.6
6 explicitly affected versions
3.4.0, 3.4.1, 3.4.2, 3.4.3, 3.4.4, 3.4.5
View affected-version evidence
{
"ranges": [
{
"events": [
{
"introduced": "3.4.0"
},
{
"fixed": "3.4.6"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"3.4.0",
"3.4.1",
"3.4.2",
"3.4.3",
"3.4.4",
"3.4.5"
]
}From 4.0.0 before 4.0.4
Fixed in 4.0.4
4 explicitly affected versions
4.0.0, 4.0.1, 4.0.2, 4.0.3
View affected-version evidence
{
"ranges": [
{
"events": [
{
"introduced": "4.0.0"
},
{
"fixed": "4.0.4"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"4.0.0",
"4.0.1",
"4.0.2",
"4.0.3"
]
}From 4.1.0 before 4.1.5
Fixed in 4.1.5
5 explicitly affected versions
4.1.0, 4.1.1, 4.1.2, 4.1.3, 4.1.4
View affected-version evidence
{
"ranges": [
{
"events": [
{
"introduced": "4.1.0"
},
{
"fixed": "4.1.5"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"4.1.0",
"4.1.1",
"4.1.2",
"4.1.3",
"4.1.4"
]
}References
- https://github.com/lcobucci/jwt/security/advisories/GHSA-7322-jrq4-x5hf
- https://nvd.nist.gov/vuln/detail/CVE-2021-41106
- https://github.com/lcobucci/jwt/commit/8175de5b841fbe3fd97d2d49b3fc15c4ecb39a73
- https://github.com/lcobucci/jwt/commit/c45bb8b961a8e742d8f6b88ef5ff1bd5cca5d01c
- https://github.com/FriendsOfPHP/security-advisories/blob/master/lcobucci/jwt/CVE-2021-41106.yaml
- https://github.com/lcobucci/jwt