PSIRTStack buffer overflow in CAPWAP daemon
Summary
A stack-based overflow vulnerability [CWE-124] in FortiOS and FortiSwitchManager CAPWAP daemon may allow a remote authenticated attacker to execute arbitrary code or command as a low privileged user via specially crafted packets.
Successful exploitation would require a large amount of effort in preparation because of stack protection and ASLR. Additionally, attacker must be able to pose as an authorized FortiAP or FortiExtender.
| Version | Affected | Solution |
|---|---|---|
| FortiOS 7.6 | 7.6.0 through 7.6.3 | Upgrade to 7.6.4 or above |
| FortiOS 7.4 | 7.4.0 through 7.4.8 | Upgrade to 7.4.9 or above |
| FortiOS 7.2 | 7.2 all versions | Migrate to a fixed release |
| FortiOS 7.0 | 7.0 all versions | Migrate to a fixed release |
| FortiOS 6.4 | 6.4 all versions | Migrate to a fixed release |
Workarounds :
Disable security fabric access into interface.
Only allow legit devices in Wifi Controller > Managed FortiAPs
Warning :
if auto-auth-extension-device is enable in config system interface, any device
can be authorized and then the vulnerability can be exploited without administrator
authorization.
Please note that auto-auth-extension-device is disabled by default
Acknowledgement
Internally discovered and reported by Gwendal Guégniaud of Fortinet Product Security Team.Timeline
2025-11-18: Initial publication2025-11-21: add workarounds