CVE-2025-20147 is a stored cross-site scripting (XSS) vulnerability found in the web-based management interface of Cisco Catalyst SD-WAN Manager (formerly Cisco SD-WAN vManage). This vulnerability arises from improper sanitization of user input within the management interface, allowing an authenticated remote attacker to inject malicious scripts that are stored and subsequently executed in the context of the web application. The vulnerability affects a wide range of Cisco Catalyst SD-WAN Manager versions, spanning multiple releases from 17.2.4 through 20.12.4.0.6, indicating a long-standing issue across many iterations of the product. Exploitation requires the attacker to have valid authentication credentials and involves user interaction, as the malicious script executes when a legitimate user accesses the affected interface. The CVSS v3.1 base score is 5.4 (medium severity), reflecting that the attack vector is network-based with low attack complexity, but requires privileges and user interaction. The impact primarily affects confidentiality and integrity, as the attacker could execute arbitrary scripts to steal session tokens, manipulate the interface, or perform actions on behalf of the user. Availability is not impacted. No known exploits are currently reported in the wild, and no patches or mitigation links are provided in the source data. The vulnerability is significant due to the critical role of Cisco Catalyst SD-WAN Manager in managing enterprise SD-WAN infrastructure, making it a valuable target for attackers seeking to compromise network management capabilities.

For European organizations, this vulnerability poses a moderate risk to the security of their SD-WAN infrastructure management. Successful exploitation could lead to unauthorized access to sensitive management functions, session hijacking, or manipulation of network configurations, potentially undermining network security and operational integrity. Given that SD-WAN managers orchestrate critical network traffic and policies, compromise could facilitate lateral movement or persistent access within enterprise networks. The requirement for authentication limits exposure to internal or credentialed threat actors, but insider threats or compromised credentials could be leveraged. Additionally, the stored XSS nature means that multiple users accessing the management interface could be affected, amplifying the risk. European enterprises relying on Cisco Catalyst SD-WAN Manager for network management, especially in sectors with stringent data protection regulations like finance, healthcare, and critical infrastructure, could face compliance and operational risks if this vulnerability is exploited.

1. Immediate mitigation should focus on restricting access to the Cisco Catalyst SD-WAN Manager interface to trusted administrators only, using network segmentation and strong access controls such as VPNs or jump hosts. 2. Enforce multi-factor authentication (MFA) for all users accessing the management interface to reduce the risk of credential compromise. 3. Monitor and audit user activities on the management interface to detect anomalous behavior indicative of exploitation attempts. 4. Implement Content Security Policy (CSP) headers and other web security controls if configurable, to limit the impact of injected scripts. 5. Regularly update and patch the Cisco Catalyst SD-WAN Manager software once Cisco releases a fix addressing this vulnerability. 6. Conduct internal security training to raise awareness about phishing and credential theft, which could enable attackers to gain the required authenticated access. 7. Consider deploying web application firewalls (WAF) with custom rules to detect and block malicious script injections targeting the management interface. 8. Review and sanitize all user inputs in custom integrations or scripts interacting with the SD-WAN Manager to prevent similar injection flaws.