A vulnerability in an API endpoint of multiple Cisco Unified Communications Products could allow an unauthenticated, remote attacker to cause high CPU utilization, which could impact access to the web-based management interface and cause delays with call processing. This API is not used for device management and is unlikely to be used in normal operations of the device.

This vulnerability is due to improper API authentication and incomplete validation of the API request. An attacker could exploit this vulnerability by sending a crafted HTTP request to a specific API on the device. A successful exploit could allow the attacker to cause a denial of service (DoS) condition due to high CPU utilization, which could negatively impact user traffic and management access. When the attack stops, the device will recover without manual intervention.

References

• https://nvd.nist.gov/vuln/detail/CVE-2023-20259
• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cucm-apidos-PGsDcdNF