CVE-2018-4063: Sierra Wireless AirLink ALEOS Unrestricted Upload of File with Dangerous Type Vulnerability

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Yes, if you run Sierra Wireless AirLink ALEOS. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2025-12-12, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-01-02; treat that as the outer limit, not the target.
• EPSS 27.3%, percentile 98: FIRST’s model estimates a 27.3% chance of exploitation activity in the next 30 days, higher than 98% of all scored CVEs (very high). EPSS is a probability, not a verdict.
• Needs an account (low (any account)). Exposure depends on who can log in.

What it is

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.

CISA’s summary

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.

Weakness type: CWE-434.

Product: Sierra Wireless AirLink ALEOS · Assigned by: talos · Published: 2019-05-06

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: low (any account)
• User interaction: none
• Scope: unchanged

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: added 2025-12-12; federal due date 2026-01-02. Known ransomware use: Unknown.
• 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.
• CISA SSVC assessment: exploitation active, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 27.26% probability of exploitation activity in the next 30 days; percentile 98.

Timeline

• 2019-05-06 — CVE record published by talos
• 2025-12-12 — Added to CISA’s Known Exploited Vulnerabilities catalog
• 2026-01-02 — CISA remediation deadline for US federal agencies
• 2026-05-22 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. Listed in CISA KEV notes (source.sierrawireless.com) source.sierrawireless.com
2. Listed in CISA KEV notes (source.sierrawireless.com) source.sierrawireless.com

Vulnerability records

1. CVE.org record CVE-2018-4063 cve.org
2. NVD entry CVE-2018-4063 nvd.nist.gov

Government

1. CISA Known Exploited Vulnerabilities catalog entry cisa.gov
2. Listed in CISA KEV notes (cisa.gov) cisa.gov

Other references from the CVE record and advisory

1. packetstormsecurity.com packetstormsecurity.com
2. ics-cert.us-cert.gov ics-cert.us-cert.gov
3. 108147 securityfocus.com
4. talosintelligence.com talosintelligence.com
5. forescout.com forescout.com

All exploited Sierra Wireless vulnerabilities · Today’s Security Digest