CVE-2018-4063

CVE-2018-4063 is an unrestricted upload of a file with a dangerous type (CWE-434) in the web server of Sierra Wireless AirLink gateways running ALEOS, where a specially crafted HTTP request can upload an executable file that becomes routable and accessible through the webserver. The flaw is triggered by an authenticated HTTP request, so an attacker must first have valid credentials for the device's web interface. With that access, an attacker can place executable code on the gateway and run it through the webserver, effectively achieving authenticated remote code execution on a device that often sits at the network edge of critical operations. Any organization running AirLink ALEOS gateways is potentially affected, and CISA notes that the impacted product may be end-of-life or end-of-service, with the recommended action being to discontinue use where mitigations are not available. The flaw was added to the CISA Known Exploited Vulnerabilities catalog on 2025-12-12, indicating known exploitation in the wild, with a high EPSS score (27.1%, 98th percentile), no public proof-of-concept, and unknown ransomware usage.

What to do: Inventory all AirLink gateways running ALEOS and check their ALEOS firmware versions against Sierra Wireless/Semtech advisories, then upgrade to currently supported firmware or discontinue use of any device CISA notes as EoL/EoS. Restrict the gateway web management interface to trusted management networks, rotate device credentials since authentication is required for exploitation, and look for unexpected uploaded files on the device webserver. Federal agencies must apply this fix per BOD 22-01 guidance following the 2025-12-12 KEV addition.