Headline
GHSA-428q-q3vv-3fq3: GraphQL grant on a property might be cached with different objects
Original message:
I found an issue with security grants on on properties in the GraphQL ItemNormalizer:
If you use something like #[ApiProperty(security: 'is_granted("PROPERTY_READ", [object, property])')] on a member of an entity, the grant gets cached and is only evaluated once, even if the object in question is a different one.
There is the ApiPlatform\GraphQl\Serializer\ItemNormalizer::isCacheKeySafe() method that seems to be intended to prevent this: https://github.com/api-platform/core/blob/88f5ac50d20d6510686a7552310cc567fcca45bf/src/GraphQl/Serializer/ItemNormalizer.php#L160-L164
and in its usage on line 90 it does indeed not create a cache key, but the parent::normalize() that is called afterwards still creates the cache key and causes the issue.
Impact
It grants access to properties that it should not.
Workarounds
Override the ItemNormalizer.
Patched at: https://github.com/api-platform/core/commit/7af65aad13037d7649348ee3dcd88e084ef771f8
Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.