CISA Flags Exploited Vulnerability in Sierra Wireless AirLink ALEOS (CVE-2018-4063)
Executive Summary
On December 12, 2025, CISA added CVE-2018-4063, a vulnerability impacting Sierra Wireless AirLink ALEOS, to its Known Exploited Vulnerabilities (KEV) Catalog, citing evidence of active exploitation. This vulnerability allows unrestricted upload of potentially malicious files, granting attackers the ability to gain remote control over affected network devices. Such vulnerabilities in network infrastructure expose organizations—including federal agencies—to heightened risks of unauthorized access, lateral movement, and disruption of operations. Federal Civilian Executive Branch agencies are mandated to remediate this issue promptly under Binding Operational Directive 22-01, and CISA encourages all enterprises to act urgently in their own environments.
This incident highlights the persistent targeting of edge network infrastructure by threat actors, a trend accelerated by increased reliance on remote and distributed operations. The rapid inclusion of this vulnerability in CISA’s KEV Catalog underscores the growing regulatory and operational pressure on organizations to adopt proactive vulnerability and network segmentation controls.
Why This Matters Now
Attackers are actively exploiting unpatched vulnerabilities in widely deployed cellular network devices, posing immediate risks to critical network infrastructure across sectors. With CISA's designation, rapid remediation is not only vital for compliance but essential to prevent exploitation, lateral movement, and potential data loss.
Attack Path Analysis
Attackers exploited CVE-2018-4063 to upload a malicious file to Sierra Wireless AirLink devices, gaining unauthorized access. Leveraging this foothold, they escalated privileges to execute arbitrary code within the device environment. The adversary then pivoted laterally, potentially moving between connected devices or internal network segments. Next, the attacker established command & control via outbound network connections to receive instructions or exfiltrate further credentials. Sensitive data or device configuration files were exfiltrated via unmonitored outbound channels. Finally, the attacker could disrupt operations by modifying device configurations or deploying destructive payloads.
Kill Chain Progression
Initial Compromise
Description
Exploitation of Sierra Wireless AirLink ALEOS CVE-2018-4063 allowed unrestricted upload of malicious files to network devices.
Related CVEs
CVE-2018-4063
CVSS 8.8An unrestricted file upload vulnerability in the upload.cgi functionality of Sierra Wireless AirLink ES450 firmware 4.9.3 allows authenticated remote attackers to execute arbitrary code.
Affected Products:
Sierra Wireless AirLink ES450 – 4.9.3
Sierra Wireless AirLink ALEOS – < 4.9.4
Exploit Status:
exploited in the wild
MITRE ATT&CK® Techniques
The listed ATT&CK techniques are mapped for SEO and filtering purposes; further detail and sub-techniques can be added in full STIX/TAXII enrichment.
Exploit Public-Facing Application
Create Account
Ingress Tool Transfer
Phishing
Command and Scripting Interpreter
Data Encrypted for Impact
System Information Discovery
Potential Compliance Exposure
Mapping incident impact across multiple compliance frameworks.
PCI DSS 4.0 – Security of System Components and Software
Control ID: 6.3.1
NYDFS 23 NYCRR 500 – Cybersecurity Policy
Control ID: 500.03
DORA – ICT Risk Management Framework
Control ID: Article 8
CISA ZTMM 2.0 – Continuous Discovery of Vulnerabilities
Control ID: Vulnerability Management - Detect and Remediate
NIS2 Directive – Supply Chain Security
Control ID: Article 21(2)(d)
Sector Implications
Industry-specific impact of the vulnerabilities, including operational, regulatory, and cloud security risks.
Telecommunications
Sierra Wireless AirLink devices widely used in telecom infrastructure create critical network vulnerabilities enabling unrestricted file uploads and potential system compromise.
Transportation
Fleet management and connected vehicle systems utilizing Sierra Wireless ALEOS face significant risks from file upload vulnerabilities compromising operational safety.
Utilities
Critical infrastructure monitoring and SCADA systems using affected Sierra Wireless devices expose power grids to potential cyberattacks through exploitation vectors.
Oil/Energy/Solar/Greentech
Remote monitoring equipment in energy sector deployments vulnerable to CVE-2018-4063 exploitation, threatening operational technology and industrial control system integrity.
Sources
- CISA Adds One Known Exploited Vulnerability to Cataloghttps://www.cisa.gov/news-events/alerts/2025/12/12/cisa-adds-one-known-exploited-vulnerability-catalogVerified
- SWI-PSA-2019-003: Technical Bulletin: Cisco Talos CVEshttps://source.sierrawireless.com/resources/airlink/software_reference_docs/technical-bulletin/sierra-wireless-technical-bulletin---swi-psa-2019-003Verified
- NVD - CVE-2018-4063https://nvd.nist.gov/vuln/detail/CVE-2018-4063Verified
Frequently Asked Questions
Cloud Native Security Fabric Mitigations and ControlsCNSF
Aviatrix CNSF controls, including zero trust segmentation, inline IPS, egress enforcement, encrypted traffic, and threat detection, would have limited or detected each phase of the attack, from initial exploitation to lateral movement and exfiltration, by enforcing least-privilege policies, inspecting traffic flows, and applying comprehensive monitoring.
Control: Inline IPS (Suricata)
Mitigation: Malicious exploitation attempt detected and blocked.
Control: Cloud Native Security Fabric (CNSF)
Mitigation: Real-time inspection of process and network activity enables early containment.
Control: Zero Trust Segmentation
Mitigation: Lateral pivoting blocked at network boundaries.
Control: Egress Security & Policy Enforcement
Mitigation: Unapproved outbound traffic to C2 endpoints detected and stopped.
Control: Encrypted Traffic (HPE) & Egress Security & Policy Enforcement
Mitigation: Data exfiltration attempts logged, restricted, or rendered unreadable.
Rapid detection of anomalous or destructive actions enabled timely response.
Impact at a Glance
Affected Business Functions
- Network Operations
- Remote Access Services
Estimated downtime: 3 days
Estimated loss: $50,000
Potential exposure of sensitive network configurations and user credentials due to unauthorized access.
Recommended Actions
Key Takeaways & Next Steps
- • Prioritize remediation of known exploited vulnerabilities in all connected network infrastructure devices.
- • Deploy zero trust segmentation to strictly limit device-to-workload communication and lateral movement.
- • Enable robust egress controls and inline IPS to detect, block, and log malicious exploitation or outbound traffic.
- • Enforce encrypted traffic for all device management and data flows to prevent interception or tampering.
- • Implement continuous anomaly detection and centralized visibility across hybrid cloud and network environments.
