mall4j through 4.0 fails to validate the sysType field in sa-token sessions, allowing storefront customers to authenticate as back-office users by reusing their session tokens. Attackers can register on the public storefront and use their customer session token to access admin endpoints lacking @PreAuthorize permission checks, including menu listings, file uploads, and configuration endpoints.
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.