CVE-2018-4063 Sierra Wireless AirLink ALEOS: dangerous file upload
In plain words: The program accepts files it should refuse, such as programs disguised as ordinary uploads. The attacker can place and run their own tools on the server.
Confirmed exploited by CISA on · US federal patch deadline Jan 2, 2026
What to do
- Install Sierra Wireless's security update for AirLink ALEOS. If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Keep a list of every internet-facing server you run so nothing is forgotten.
- Patch anything in this catalog first, ahead of normal patch cycles.
- Put admin and file-transfer apps behind a VPN or single sign-on instead of the open internet.
Who is affected
Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.
What's at risk: Mass data theft and ransomware: a single flaw in a file-transfer or email server has exposed thousands of organisations at once.
The details
- Official name
- Sierra Wireless AirLink ALEOS Unrestricted Upload of File with Dangerous Type Vulnerability
- Product
- Sierra Wireless AirLink ALEOS
- CISA description
- Sierra Wireless AirLink ALEOS contains an unrestricted upload of file with dangerous type vulnerability. A specially crafted HTTP request can upload a file, resulting in executable code being uploaded, and routable, to the webserver. An attacker can make an authenticated HTTP request to trigger this vulnerability. The impacted product could be end-of-life (EoL) and/or end-of-service (EoS). Users should discontinue product utilization.
- Type of flaw
- Dangerous file upload (CWE-434)
- Confirmed exploited
- Dec 12, 2025
- US federal patch deadline
- Jan 2, 2026
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Answering about CVE-2018-4063 ·
Questions about CVE-2018-4063
Is CVE-2018-4063 being exploited?
Yes. CISA added CVE-2018-4063 to its Known Exploited Vulnerabilities catalog on Dec 12, 2025, which means there is reliable evidence of real-world attacks.
How do I fix CVE-2018-4063?
Install Sierra Wireless's security update for AirLink ALEOS. If no update exists, follow the vendor's workaround or stop using the product until one ships. Keep a list of every internet-facing server you run so nothing is forgotten.
Am I affected by CVE-2018-4063?
Only if you use Sierra Wireless AirLink ALEOS. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.