Sierra Wireless AirLink ALEOS Remote Code Execution via File Upload

Historical catalog analysis: CISA added this entry on December 12, 2025. The entry reflects catalog information retrieved on August 31, 2026, not a snapshot archived on the inclusion date. Check current vendor guidance before acting.

What the vulnerability is

CVE-2018-4063 is an unrestricted upload of file with dangerous type vulnerability (CWE-434) affecting Sierra Wireless AirLink ALEOS. The flaw allows an authenticated attacker to send a specially crafted HTTP request to upload executable code directly to the webserver, where it becomes routable.

Exposure and applicability

This vulnerability applies to infrastructure owners utilizing Sierra Wireless AirLink ALEOS devices. Because the attack vector requires authentication, exposure is highest in environments where administrative credentials for these gateways have been compromised or are weakly managed.

Crucially, some affected products may have reached end-of-life (EoL) or end-of-service (EoS) status. This means that traditional patching cycles may no longer be viable for all deployed hardware versions, increasing the risk of permanent exposure if the devices remain in production.

Remediation priorities

Based on the reported vulnerability and product lifecycle status, we analyze the following priority actions:

1. Asset Inventory and Lifecycle Audit: Identify all AirLink ALEOS devices currently in production. Determine which specific hardware models have reached EoL/EoS status. This is a prerequisite for deciding between mitigation and decommissioning.
2. Implementation of Vendor Mitigations: For devices still supported, apply the mitigations provided by the vendor.
3. Hardware Decommissioning: For assets that are EoL/EoS or where mitigations cannot be verified, our analysis suggests discontinuing product utilization to eliminate the attack surface entirely.
4. Credential Rotation and Access Control: Since the vulnerability requires authentication, restricting HTTP management access to trusted internal networks and rotating administrative passwords could reduce the likelihood of an attacker successfully triggering the upload.

How to validate remediation

Verification must go beyond a version check, as EoL status may complicate the availability of patches.

• For mitigated systems: Defenders should verify that the specific HTTP request path used for file uploads is either disabled or strictly validated against dangerous file types, according to vendor guidance.
• For decommissioned systems: Validation consists of confirming the physical removal or logical disconnection of the EoL/EoS hardware from the network.
• Residual Risk: If mitigations are applied but the device remains in service, residual risk persists if an attacker gains administrative credentials. Only decommissioning removes the vulnerability entirely.

Limits and open questions

It is currently unknown whether this vulnerability has been utilized in known ransomware campaigns. Additionally, because some products are EoL/EoS, it remains unclear if a universal patch exists for all affected versions or if only specific compensating controls are available.

Source and editorial note

CVE-2018-4063: Sierra Wireless AirLink ALEOS Unrestricted Upload of File with Dangerous Type Vulnerability · Source date: December 12, 2025 · Retrieved August 31, 2026.

Material facts are tied to the cited primary source. Recommendations are independent defensive analysis unless attributed to the source. Confirm consequential decisions against current authoritative guidance.

Archive date: December 15, 2025. The displayed post date is assigned three days after the source date to organize this retrospective archive; it does not mean this site published the analysis then. First published by this site: September 26, 2026 at 01:02 UTC.

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