A vulnerability in the web-based interface of Cisco Unified Communications Manager and Cisco Unified Communications Manager Session Management Edition (SME) could allow an unauthenticated, remote attacker to access sensitive information or cause a denial of service (DoS) condition. The vulnerability is due to improper restrictions on XML entities. An attacker could exploit this vulnerability by sending malicious requests to an affected system that contain references in XML entities. A successful exploit could allow the attacker to retrieve files from the local system, resulting in the disclosure of sensitive information, or cause the application to consume available resources, resulting in a DoS condition.
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20191002-cucm-xxe