Vulnerability · Published Jan 6, 2022 · Assigned by mitre

CVE-2021-44878

High 7.5

In plain English

A high-severity security flaw in the org.pac4j:pac4j-oidc package (Maven). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 61% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)7.5High

Exploit odds (30 days)0.9%top 39.4% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official description

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 & fixed versions

Ecosystem	Package	Fixed in	Advisory
Maven	org.pac4j:pac4j-oidc	4.5.5	GHSA-xhw6-hjc9-679m
Maven	org.pac4j:pac4j-oidc	5.3.1	GHSA-xhw6-hjc9-679m

Affected products (as reported)

Vendor	Product	Versions
n/a	n/a	n/a

References

https://github.com/pac4j/pac4j/commit/22b82ffd702a132d9f09da60362fc6264fc281ae x_refsource_MISC
https://openid.net/specs/openid-connect-core-1_0.html#IDToken x_refsource_MISC
https://www.pac4j.org/blog/cve_2021_44878_is_this_serious.html x_refsource_MISC