Description
In jsonwebtoken node module before 4.2.2 it is possible for an attacker to bypass verification when a token digitally signed with an asymmetric key (RS/ES family) of algorithms but instead the attacker send a token digitally signed with a symmetric algorithm (HS* family).
Remediation
References
https://www.timmclean.net/2015/02/25/jwt-alg-none.html
https://nodesecurity.io/advisories/17
https://github.com/auth0/node-jsonwebtoken/commit/1bb584bc382295eeb7ee8c4452a673a77a68b687
https://auth0.com/blog/2015/03/31/critical-vulnerabilities-in-json-web-token-libraries/