Sierra Wireless AirLink ALEOS Unrestricted Upload of File with Dangerous Type Vulnerability
n/a — Sierra Wireless
An exploitable remote code execution vulnerability exists in the upload.cgi functionality of Sierra Wireless AirLink ES450 FW 4.9.3. 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.
8.8
27.9%
Vector breakdown
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Published
- May 6, 2019
- Modified
- May 22, 2026
- Added to KEV
- Dec 12, 2025
- Federal patch due
- Jan 2, 2026
CISA required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Weakness classification
Proof-of-concept & exploitation references
Weaponization
Public repositories whose name or description references CVE-2018-4063, found via a live GitHub search at request time. These are community-sourced signals, not a verified working exploit - cross-check each one before relying on it, and treat higher star counts and recent activity as (weak) corroboration, not proof.
No public GitHub repositories referencing CVE-2018-4063 were found at last check. Absence here is not proof no exploit exists - see the references below for vendor advisories and write-ups.
References
Frequently asked questions
What is CVE-2018-4063?
An exploitable remote code execution vulnerability exists in the upload.cgi functionality of Sierra Wireless AirLink ES450 FW 4.9.3. 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.
How severe is CVE-2018-4063?
CVE-2018-4063 has a CVSS base score of 8.8 out of 10 (CVSS 3.1).
Is CVE-2018-4063 actively exploited in the wild?
Yes. CVE-2018-4063 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added Dec 12, 2025, meaning CISA has confirmed evidence of active exploitation.
What is the EPSS score for CVE-2018-4063?
27.9% - meaning FIRST.org's EPSS model estimates a 27.9% probability this vulnerability will be exploited in the wild within 30 days (98% percentile among all scored CVEs).
What type of vulnerability is CVE-2018-4063?
CVE-2018-4063 is classified under CWE-434 (CWE-434 Unrestricted Upload of File with Dangerous Type).
Cross-checked against
Impactr finds and proves whether CVE-2018-4063 - or flaws like it - are actually reachable in your own web apps and APIs, with a reproducible exploit as evidence.
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