Cisco has rolled out software patches to address a severe security vulnerability, tracked as CVE-2025-20188, in its IOS XE Wireless Controller software. The flaw, which has been assigned the highest possible CVSS score of 10.0, could allow unauthenticated remote attackers to gain full root access on affected systems.
The issue stems from a hard-coded JSON Web Token (JWT) embedded within the IOS XE Wireless Controller, which can be exploited through specifically crafted HTTPS requests sent to the Access Point (AP) image download interface. If successful, this exploit could enable attackers to upload malicious files, conduct path traversal attacks, and execute arbitrary commands with root-level privileges.
“This vulnerability is due to the presence of a hard-coded JSON Web Token (JWT) on an affected system,” Cisco stated in its security advisory published on May 7, 2025. “A successful exploit could allow the attacker to upload files, perform path traversal, and execute arbitrary commands with root privileges.”
Conditions for Exploitation with CVE-2025-20188
The critical vulnerability affects only those systems where the Out-of-Band AP Image Download feature is enabled. Fortunately, this feature is disabled by default in the IOS XE Wireless Controller configuration. However, if administrators have enabled this functionality, systems are exposed to this severe risk.
Network administrators can determine if this vulnerable feature is active by running the command:
arduino
CopyEdit
show running-config | include ap upgrade
If the output includes an upgrade method to HTTPS, the device is at risk, and immediate action is required.
Affected Cisco Products
The flaw impacts several Cisco IOS XE Wireless Controller devices, provided they are running vulnerable software versions and have the Out-of-Band AP Image Download feature enabled:
- Catalyst 9800-CL Wireless Controllers for Cloud
- Catalyst 9800 Embedded Wireless Controllers for the 9300, 9400, and 9500 Series Switches
- Catalyst 9800 Series Wireless Controllers
- Embedded Wireless Controller on Catalyst Access Points
Cisco clarified that devices not functioning as Wireless LAN Controllers (WLCs), as well as products running IOS, IOS XR, Meraki software, NX-OS, and AireOS, are not affected by CVE-2025-20188.
No Workarounds, Only Fixes
Unlike some security issues that can be temporarily mitigated with configuration tweaks, CVE-2025-20188 does not have any viable workarounds. That said, administrators can disable the Out-of-Band AP Image Download feature as a temporary mitigation measure. This forces the system to revert to the default CAPWAP method for AP image downloads, which is unaffected by the flaw.
However, Cisco cautions that disabling this feature might have unintended consequences in some environments. “Customers should not deploy any workarounds or mitigations before first evaluating the applicability to their own environment and any impact to such environment,” the company noted.
Software Updates Now Available
Cisco has released free software updates that resolve the vulnerability. These patches are available through the company’s standard update channels for customers with valid service contracts and software licenses.
Users are advised to confirm that their devices have sufficient memory and are compatible with the new software versions before proceeding with the upgrade. The company emphasizes that security fixes do not grant access to additional features or new software licenses—customers must have appropriate entitlements for any upgrades they download.
For customers unsure about their licensing status or how to obtain the correct software fix, Cisco recommends visiting the Cisco Support and Downloads portal or contacting the Cisco Technical Assistance Center (TAC).
Conclusion
The rapid identification and patching of this critical flaw—stemming from a hard-coded JWT in the IOS XE Wireless Controller—emphasizes the ongoing importance of proactive network defense, especially in systems with high privilege access.
Cisco urges administrators to promptly apply available fixes, disable the vulnerable feature where feasible, and regularly consult the full set of advisories to ensure comprehensive protection.
