A vulnerability in the XCP Authentication Service of the Cisco Unified Communications Manager IM & Presence Service (Unified CM IM&P) could allow an unauthenticated, remote attacker to cause a temporary service outage for all Cisco Unified CM IM&P users who are attempting to authenticate to the service, resulting in a denial of service (DoS) condition. This vulnerability is due to improper validation of user-supplied input. An attacker could exploit this vulnerability by sending a crafted login message to the affected device. A successful exploit could allow the attacker to cause an unexpected restart of the authentication service, preventing new users from successfully authenticating. Exploitation of this vulnerability does not impact Cisco Unified CM IM&P users who were authenticated prior to an attack.
The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.
The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor.