CVE-2025-20190 is a medium-severity vulnerability affecting Cisco IOS XE Wireless Controller Software, specifically within the lobby ambassador web interface. The vulnerability arises from improper access control mechanisms that allow an authenticated attacker with lobby ambassador user credentials to perform unauthorized actions. Specifically, an attacker can send crafted HTTP requests to the device's API to remove arbitrary user accounts, including those with administrative privileges. This could lead to significant disruption in device management and security posture, as deleting administrative users may lock out legitimate administrators or enable further malicious activities by weakening access controls. The vulnerability requires the attacker to have valid lobby ambassador credentials, which are not configured by default, reducing the attack surface but still posing a risk if such credentials are compromised or misconfigured. The affected versions include multiple releases of Cisco IOS XE Software (17.6.8, 17.9.6, 17.9.6a, 17.12.1z2, 17.12.1z3, 17.15.1, and 17.15.1x). The CVSS v3.1 base score is 6.5, reflecting a medium severity with network attack vector, low attack complexity, and requiring privileges but no user interaction. No known exploits are currently reported in the wild, but the vulnerability’s nature suggests potential for impactful misuse if exploited. Cisco has not yet published patches or mitigation details at the time of this report.

For European organizations, the impact of this vulnerability can be significant, especially for enterprises and service providers relying on Cisco IOS XE Wireless Controllers to manage wireless infrastructure. Successful exploitation could lead to unauthorized deletion of user accounts, including administrators, resulting in loss of control over network devices, potential denial of management access, and increased risk of further compromise. This could disrupt wireless network availability and security, impacting business operations, data confidentiality, and compliance with regulations such as GDPR. Organizations in sectors with critical infrastructure or sensitive data (e.g., finance, healthcare, government) are particularly at risk. The requirement for lobby ambassador credentials limits exploitation to insider threats or attackers who have already compromised lower-privileged accounts, but the ease of privilege escalation through user deletion elevates the threat. The absence of user interaction and network-based attack vector means remote exploitation is feasible once credentials are obtained, increasing the urgency for mitigation in environments where lobby ambassador accounts exist or could be created.

1. Immediately audit and restrict lobby ambassador user accounts: Remove any unnecessary lobby ambassador accounts and enforce strong, unique passwords. 2. Implement strict access controls and monitoring on the lobby ambassador interface to detect unusual API requests or user deletions. 3. Employ network segmentation and firewall rules to limit access to the wireless controller management interfaces only to trusted administrative networks. 4. Regularly review and update user account privileges to ensure least privilege principles are enforced. 5. Monitor logs for suspicious activity related to user account management, especially deletions. 6. Stay alert for Cisco’s official patches or advisories and apply updates promptly once available. 7. Consider multi-factor authentication (MFA) for all administrative and privileged accounts to reduce the risk of credential compromise. 8. Conduct security awareness training for administrators to recognize phishing or credential theft attempts targeting lobby ambassador accounts.