Sierra Wireless AirLink ALEOS Unrestricted Upload of File with Dangerous Type Vulnerability
Sierra Wireless · AirLink ALEOS
8.8HighCVSS 3.1
Recommended action
Protect now
CISA confirms exploitation in the wild and lists 2026-01-02 as the remediation due date.
Fix not verified
Optional official sources
National CERT insights ?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.
Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.
Official European source
ENISA European Vulnerability Database
Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.
1 current
ENISA EUVD identifier
EUVD-2018-15849
CISA KEV mirrored by ENISA
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.
EUVD state
Present in the current official mapping
Known exploitation
Recorded by ENISA since 12 Dec 2025. Evidence sources: cisa_kev.
ENISA score
8.8 · CVSS 3.1
Advisory evidence
1 linked advisory record
Explicit mitigation evidence
Only statements that explicitly mention a fix, patch, update, workaround or mitigation are shown here.
csaf_cisa · ICSA-19-122-03Sierra Wireless AirLink ALEOS (Update B)
Recommended actionProtect now
CISA confirms exploitation in the wild and lists 2026-01-02 as the remediation due date.
Fix not verified
01
What, why and how
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.
What
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.
Why
The upload path does not sufficiently restrict the type, name, location or later execution of attacker-supplied files.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
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.
Why
The upload path does not sufficiently restrict the type, name, location or later execution of attacker-supplied files.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation ?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.Confirmed in the wild
CISA added this CVE to its Known Exploited Vulnerabilities catalogue on 2025-12-12.
Public PoC / exploit material ?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.Reference recorded
A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.
Likely attack path
a network path → Unrestricted Upload of File with Dangerous Type → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness ?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-434: Unrestricted Upload of File with Dangerous Type. The product allows the upload or transfer of dangerous file types that are automatically processed within its environment.
CVSS vector ?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkCWE-434CISA KEVPublic exploit reference
A
Official authority intelligence
Only matched European and national findings are included. Language selectors and unavailable sources are omitted.
ENISA EUVD · EUVD-2018-15849Known-exploited evidence recorded
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.
Operational remediation based on structured source evidence.
Status ?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix not verified
Affected
Sierra Wireless AirLink ES450 FW 4.9.3
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 6 May 2019 · Last source change 22 May 2026, 13:18 UTC · CWE-434 · Unrestricted Upload of File with Dangerous Type
CVE recordCVE.org · 5.2
CVSS sourceNIST NVD
EPSS source ?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.FIRST · tracked since 2026-09-01
European sourceENISA EUVD · EUVD-2018-15849
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCISA ADP
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
CVE-2018-4063: Sierra Wireless AirLink ALEOS Unrestricted Upload of File with Dangerous Type Vulnerability | BlackTree