GHSA-25cw-98hg-g3cg

Summary

The Admidio SAML Identity Provider implementation discards the return value of its validateSignature() method at both call sites (handleSSORequest() line 418 and handleSLORequest() line 613). The method returns error strings on failure rather than throwing exceptions, but the developer believed it would throw (per comments on lines 416 and 611). This means the smc_require_auth_signed configuration option is completely ineffective — unsigned or invalidly-signed SAML AuthnRequests and LogoutRequests are processed identically to properly signed ones.

Details

The validateSignature() method at src/SSO/Service/SAMLService.php:355 has three possible return paths:

// Line 355-392
public function validateSignature(SAMLClient $client, SamlMessage $message, bool $required = false): bool|string {
    global $gL10n;
    $certPem = $client->getValue('smc_x509_certificate');
    if (!$certPem) {
        if ($required) {
            return $gL10n->get('SYS_SSO_SAML_SIGNATURE_KEY_MISSING'); // Returns STRING, not throw
        } else {
            return false;
        }
    }
    // ...
    $signatureReader = $message->getSignature();
    if (is_null($signatureReader)) {
        if ($required) {
            return $gL10n->get('SYS_SSO_SAML_SIGNATURE_MISSING'); // Returns STRING, not throw
        } else {
            return false;
        }
    }
    try {
        $ok = $signatureReader->validate($key);
        if ($ok) {
            return true;
        } else {
            return $gL10n->get('SYS_SSO_SAML_SIGNATURE_FAILED'); // Returns STRING, not throw
        }
    } catch (Exception $ex) {
        return $gL10n->get('SYS_SSO_SAML_SIGNATURE_FAILED'); // Returns STRING, not throw
    }
}

Both call sites discard the return value entirely:

// Line 416-419 in handleSSORequest()
// Validate signatures. Will throw an exception    <-- INCORRECT COMMENT
if ($client->getValue('smc_require_auth_signed') ||...