CVE-2024-58267: Rancher CLI SAML authentication is vulnerable to phishing attacks

A vulnerability has been identified within Rancher Manager whereby the SAML authentication from the Rancher CLI tool is vulnerable to phishing attacks. The custom authentication protocol for SAML-based providers can be abused to steal Rancher’s authentication tokens.

Rancher Manager deployments without SAML authentication enabled are not affected by this vulnerability.

An attacker can generate a phishing SAML login URL which contains a publicKey and requestId controlled by the attacker. The attacker can then give the link to another user (eg: admin) and if the victim goes to the link unsuspectingly, they might not notice the bad parameters in the URL. The user will be prompted to login and might believe that its session has ended so they need to re-login. By clicking on the link, they will be logged in and an encrypted token will be created with the attacker’s public key. The attacker can then decrypt the victim’s Rancher token, enabling the attack

Please consult the associated MITRE ATTACK Techniques - Privilege Escalation for further information about this category of attack.