CVE-2021-44878

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.

Category

7.5
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.04%
Vendor Advisory pac4j.org
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://github.com/pac4j/pac4j/commit/22b82ffd702a132d9f09da60362fc6264fc281ae third party advisory patch
https://openid.net/specs/openid-connect-core-1_0.html#IDToken product third party advisory
https://www.pac4j.org/blog/cve_2021_44878_is_this_serious.html mitigation vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-44878?
CVE-2021-44878 has been scored as a high severity vulnerability.
How to fix CVE-2021-44878?
To fix CVE-2021-44878, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-44878 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-44878 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
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