CVE intelligence and bounded remediation

CVE-2021-0260 — Juniper Junos security vulnerability

High CVSS 7.5

An improper authorization vulnerability in the Simple Network Management Protocol daemon (snmpd) service of Juniper Networks Junos OS leads an unauthenticated attacker being able to perform SNMP read actions, an Exposure of System Data to an Unauthorized Control Sphere, or write actions to OIDs that support write operations, against the device without authentication. This issue affects: Juniper Networks Junos OS: 17.2 version 17.2R1 and later versions; 17.3 versions prior to 17.3R3-S9; 17.4 versions prior to 17.4R2-S12, 17.4R3-S5; 18.1 versions prior to 18.1R3-S13; 18.2 versions prior to 18.2R3-S8; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R1-S8, 18.4R2-S5, 18.4R3; 19.1 versions prior to 19.1R2; 19.2 versions prior to 19.2R1-S6, 19.2R2; 19.3 versions prior to 19.3R2. This issue does not affect Juniper Networks Junos OS versions prior to 17.2R1.

Severity
High
CVSS
7.5 (2.0)
Published
2021-04-22
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-285, CWE-497

Affected products

  • juniper / junos / 17.2

Showing 1 representative product identities from 157 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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