CVE-2025-20375 is a vulnerability identified in the web user interface of Cisco Unified Contact Center Express (UCCX), a widely used contact center management solution. The flaw arises from insufficient input validation in specific UI features that handle file uploads. An attacker who has authenticated with valid administrative credentials can exploit this vulnerability by uploading specially crafted files through the web UI. Because the system does not properly validate the file types or contents, the attacker can upload and execute arbitrary files on the underlying operating system. This leads to remote code execution capabilities, allowing the attacker to gain control over the system, potentially access sensitive data, manipulate system configurations, or disrupt services. The vulnerability affects a broad range of UCCX versions from 10.5(1)SU1 through 15.0.1 and various subversions, indicating a long-standing issue across multiple releases. The CVSS v3.1 base score is 6.5, reflecting medium severity due to the requirement for high privileges (administrative credentials) and no user interaction. The attack vector is network-based, and the scope remains unchanged, meaning the impact is confined to the vulnerable component. No public exploits have been reported yet, but the potential for significant damage exists if exploited. The vulnerability was reserved in October 2024 and published in November 2025, with Cisco likely to release patches or mitigations soon.

The impact of CVE-2025-20375 is significant for organizations using Cisco Unified Contact Center Express, as it allows an attacker with administrative access to execute arbitrary code on the underlying operating system. This can lead to full system compromise, including unauthorized access to sensitive customer data, disruption of contact center operations, and potential lateral movement within the corporate network. The confidentiality and integrity of the system are severely affected, although availability impact is not directly indicated. Given that contact centers often handle sensitive personal and financial information, exploitation could result in data breaches, regulatory penalties, and reputational damage. The requirement for administrative credentials limits the attack surface but does not eliminate risk, especially in environments where credential theft or insider threats are possible. The vulnerability could also be leveraged as a foothold for further attacks against enterprise infrastructure. Organizations with large-scale deployments of Cisco UCCX, especially in finance, healthcare, and government sectors, face heightened risk due to the critical nature of their services and data.

To mitigate CVE-2025-20375, organizations should immediately verify and restrict administrative access to the Cisco UCCX web UI, enforcing strong authentication mechanisms such as multi-factor authentication (MFA) to reduce the risk of credential compromise. Network segmentation should be applied to limit access to the management interface only to trusted administrators. Monitoring and logging of administrative activities should be enhanced to detect any anomalous file upload attempts. Organizations should apply any available patches or updates from Cisco as soon as they are released. In the absence of patches, consider disabling or restricting file upload functionality in the web UI if feasible. Conduct regular audits of user accounts and permissions to ensure least privilege principles are enforced. Additionally, implement endpoint protection and intrusion detection systems to identify and block suspicious activities related to file execution on the UCCX servers. Finally, maintain up-to-date backups and incident response plans to quickly recover from potential compromises.