If an OpenID Connect provider supports the "none" algorithm (i.e., tokens with no signature), pac4j v5.3.0 (and prior) does not refuse it without an explicit configuration on its side or for the "idtoken" response type which is not secure and violates the OpenID Core Specification. The "none" algorithm does not require any signature verification when validating the ID tokens, which allows the malicious user to bypass the token validation by injecting a malformed ID token using "none" as the value of "alg" key in the header with an empty signature value.
| Vulnerable Product | Search on Vulmon | Subscribe to Product |
|---|---|---|
pac4j pac4j |
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