21Nis
What are the risks of using wildcard in context path of OIDC/OAuth redirect_uri?
I'm using Keycloak for my authentication needs. It allows me to use * as wildcard when whitelisting redirect_uris for OIDC clients. What are the risks of using * in context path of redirect_uri? For example, what could attacker do if I registered following as valid redirect-uri https://www.domainownedbyme.com/*?
I understand that having wildcard in domain part of redirect_uri is vulnerable to attacks. For example https://*.foo.com would allow attacker to redirect user into something like https://attackers.evilsite.net/.foo.com. But I have no idea of how attacker could use wildcard that is set in context path of redirect_uri.
