A vulnerability was found in Apereo CAS 5.2.6. It has been classified as problematic. This affects the function ResponseEntity of the file cas-5.2.6webapp-mgmtcas-management-webapp-supportsrcmainjavaorgapereocasmgmtserviceswebManageRegisteredServicesMultiActionController.java. The manipulation of the argument Query leads to inefficient regular expression complexity. It is possible to initiate the attack remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
The product does not properly control the allocation and maintenance of a limited resource.
Mitigation of resource exhaustion attacks requires that the target system either:
The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.