high7.5
CVE-2021-44878
Pac4j token validation bypass if OpenID Connect provider supports none algorithm
Impact
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 attacker 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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| maven | org.pac4j:pac4j-oidc | < 4.5.5 | 4.5.5 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Pac4j | Pac4j | before 4.5.5 from 5.0.0 before 5.3.1 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/pac4j/pac4j/commit/22b82ffd702a132d9f09da60362fc6264fc281ae
- https://openid.net/specs/openid-connect-core-1_0.html#IDToken
- https://www.pac4j.org/blog/cve_2021_44878_is_this_serious.html
- https://github.com/advisories/GHSA-xhw6-hjc9-679m
- https://nvd.nist.gov/vuln/detail/CVE-2021-44878
- https://github.com/pac4j/pac4j/commit/09684e0de1c4753d22c53b8135d4ef61cfda76f7
- https://github.com/pac4j/pac4j/commit/9c87bbc536ed5d05f940ae015403120df2935589
- https://www.pac4j.org/4.5.x/docs/release-notes.html