Severe Security Flaw in Cisco WLCs enables Remote Root Access (CVE-2025-20188)

Summary

Cyble's Security Update Advisory provides a synopsis of the latest vulnerability patches released by various vendors. This advisory discusses an Arbitrary File Upload vulnerability impacting Cisco IOS XE Software for Wireless LAN Controllers (WLCs). Classified as a critical severity issue, this vulnerability could enable an attacker to upload files, carry out path traversal, and execute arbitrary commands with root privileges, potentially giving them full control over the affected system.

Based on naming standards followed by Common Vulnerabilities and Exposures (CVE) and severity standards as defined by the Common Vulnerability Scoring System (CVSS), vulnerabilities are classified as high, medium, and low vulnerabilities.

Vulnerability Details

Arbitrary File Upload

CVE-2025-20188

CVSSv3.1

10

Severity

Critical

Vulnerable Versions

Cisco products, if they are running a vulnerable release of Cisco IOS XE Software for WLCs and have

the Out-of-Band AP Image Download feature enabled:

• Catalyst 9800-CL Wireless Controllers for Cloud

• Catalyst 9800 Embedded Wireless Controller for Catalyst 9300, 9400, and 9500 Series Switches

• Catalyst 9800 Series Wireless Controllers

• Embedded Wireless Controller on Catalyst APs

IOS XE Version: 17.7.1, 17.8.1, 17.9.1, 17.9.2, 17.9.3, 17.9.4, 17.9.4a, 17.9.5, 17.10.1, 17.10.1b, 17.11.1, 17.11.99SW, 17.12.1, 17.12.2, 17.12.3, 17.13.1, 17.14.1

Description

A vulnerability in the Out-of-Band Access Point (AP) Image Download feature of Cisco IOS XE Software for Wireless LAN Controllers (WLCs) could allow a remote, unauthenticated attacker to upload arbitrary files to the targeted system. The issue arises from a hard-coded JSON Web Token (JWT) present in the affected systems. By sending specially crafted HTTPS requests to the AP image download interface, an attacker could exploit this flaw to upload files, carry out path traversal, and execute arbitrary commands with root-level privileges.

Additional Information

To determine whether a device is configured with the Out-of-Band AP Image Download feature enabled, use the show running-config | include ap upgrade command. If the command returns the AP upgrade method https, the feature is enabled, and the device is affected by this vulnerability.

X.B. of the Cisco Advanced Security Initiatives Group (ASIG) found this vulnerability during internal security testing.

Cisco offers the Cisco Software Checker to assist customers in identifying their exposure to vulnerabilities in Cisco IOS and IOS XE Software. - Link

Mitigation

Administrators can disable the Out-of-Band AP Image Download feature. With this feature disabled, AP image download will use the CAPWAP method for the AP image update feature, and this does not impact the AP client state. Cisco strongly recommends implementing this mitigation until an upgrade to a fixed software release can be performed.

Note: While this mitigation has been deployed and was proven successful in a test environment, customers should determine the applicability and effectiveness in their own environment and under their own use conditions

Patch Link

Link

Our Recommendations

• Implement the latest patch released by the official vendor: Regularly update all software and hardware systems with the latest patches from official vendors to mitigate vulnerabilities and protect against exploits. Establish a routine schedule for patch application and ensure critical patches are applied immediately.

• Implement a robust patch management process: Develop a comprehensive patch management strategy that includes inventory management, patch assessment, testing, deployment, and verification. Automate the process where possible to ensure consistency and efficiency.

• Incident response and recovery plan: Create and maintain an incident response plan that outlines procedures for detecting, responding to, and recovering from security incidents. Regularly test and update the plan to ensure its effectiveness and alignment with current threats.

• Monitoring and logging malicious activities across the network: Implement comprehensive monitoring and logging solutions to detect and analyze suspicious activities. Use SIEM (Security Information and Event Management) systems to aggregate and correlate logs for real-time threat detection and response.

• To mitigate risks associated with End-of-Life (EOL) products: Organizations should proactively identify and assess their criticality, then plan for timely upgrades or replacements.

Conclusion

Cisco Wireless LAN Controllers (WLCs) are key devices that manage and secure wireless access points (APs) in enterprise and campus networks, providing centralized control and configuration. They are widely deployed in environments such as businesses, universities, and healthcare facilities to ensure seamless and secure Wi-Fi connectivity.

However, the recently disclosed critical vulnerability in Cisco’s IOS XE operating system, which runs on these WLCs, could allow attackers to upload files, perform path traversal, and execute arbitrary commands with root privileges. To mitigate the risk of exploitation and prevent potential security breaches, urgent patching of all affected systems is strongly recommended. Immediate action is necessary to secure the network and protect sensitive data from malicious exploitation.