High, CVSS 8.0PackagistPublished
phpCAS vulnerable to Service Hostname Discovery Exploitation
CVE-2022-39369 · GHSA-8q72-6qq8-xv64
- Affected
- Packagist apereo/phpcas < 1.6.0
- Fixed in
- 1.6.0· Vendor fix available
- Issue
- Impact The phpCAS library uses HTTP headers to determine the service URL used to validate tickets. This allows an attacker to control the host header and use a valid ticket granted for any authorized service in the same SSO realm (CAS server) to authenticate to the service protected by phpCAS. Depending on the settings of the CAS server service registry in worst case this may be any other service URL (if the allowed URLs are configured to "^(https)://.") or may be strictly limited to known and authorized services in the same SSO federation if proper URL service validation is applied. This vulnerability may allow an attacker to gain access to a victim's account on a vulnerable CASified service without victim's knowledge, when the victim visits attacker's website while being logged in to the same CAS server. Patch phpCAS 1.6.0 is a major version upgrade that starts enforcing service URL discovery validation, because there is unfortunately no 100% safe default config to use in PHP.…
Recommended action: Upgrade to 1.6.0 or later, then redeploy and verify.A vendor fix does not resolve your finding until you verify it in your own systems.