OneLogin AD Connector JWT Authentication Bypass via Exposed Signing Key

A cryptographic authentication bypass vulnerability exists in OneLogin AD Connector prior to 6.1.5 due to the exposure of a tenant’s SSO JWT signing key via the /api/adc/v4/configuration endpoint. An attacker in possession of the signing key can craft valid JWT tokens impersonating arbitrary users within a OneLogin tenant. The tokens allow authentication to the OneLogin SSO portal and all downstream applications federated via SAML or OIDC. This allows full unauthorized access across the victim’s SaaS environment.