CVE intelligence and bounded remediation

CVE-2019-0041 — On EX4300-MP Series devices with any lo0 filters applied, transit network traffic may reach the control plane via loopback interface (lo0)

High CVSS 8.6

On EX4300-MP Series devices with any lo0 filters applied, transit network traffic may reach the control plane via loopback interface (lo0). The device may fail to forward such traffic. This issue affects Juniper Networks Junos OS 18.2 versions prior to 18.2R1-S2, 18.2R2 on EX4300-MP Series. This issue does not affect any other EX series devices.

Severity
High
CVSS
8.6 (3.1)
Published
2019-04-10
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-284

Affected products

  • juniper / junos / 18.2

Showing 1 representative product identities from 2 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Authorization bypass, IDOR, and cross-tenant access

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Map object and action authorization checks across API, UI, batch, import/export, and background-job paths.
  • Identify tenant, ownership, role, and policy boundaries for affected resources and administrative operations.
  • Use synthetic fixtures to compare intended access matrices without accessing another user's real data.

Remediate safely

  • Enforce server-side authorization at each resource access and state transition using the authenticated principal and trusted tenant context.
  • Scope data queries by tenant and ownership; treat client-supplied identifiers, roles, and policy claims as untrusted.
  • Add deny-by-default policy tests for horizontal and vertical access across every affected transport.

Authoritative sources

Complete CVE record and remediation plan

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