CVE intelligence and bounded remediation

CVE-2021-0231 — Juniper Junos security vulnerability

Medium CVSS 6.8

A path traversal vulnerability in the Juniper Networks SRX and vSRX Series may allow an authenticated J-web user to read sensitive system files. This issue affects Juniper Networks Junos OS on SRX and vSRX Series: 19.3 versions prior to 19.3R2-S6, 19.3R3-S1; 19.4 versions prior to 19.4R2-S4, 19.4R3; 20.1 versions prior to 20.1R1-S4, 20.1R2; 20.2 versions prior to 20.2R1-S3, 20.2R2; This issue does not affect Juniper Networks Junos OS versions prior to 19.3R1.

Severity
Medium
CVSS
6.8 (2.0)
Published
2021-04-22
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-22

Affected products

  • juniper / junos / 19.3
  • juniper / junos / 19.4

Showing 2 representative product identities from 24 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Path traversal, unsafe upload, and file handling

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

Check exposure

  • Trace untrusted filenames, archive entries, URLs, and path segments into read, write, include, extraction, and upload operations.
  • Identify filesystem roots, mount permissions, symbolic-link behavior, archive handling, and whether uploaded content is web-accessible or executable.
  • Review canonicalization and containment checks across supported operating systems and storage backends.

Remediate safely

  • Generate server-side storage identifiers and resolve paths beneath a fixed root using filesystem-aware containment checks.
  • Reject absolute, parent-relative, alternate-separator, device, link, and archive entries that escape the intended root.
  • Store uploads outside executable or served paths, validate type and size, and use private atomic temporary files.

Authoritative sources

Complete CVE record and remediation plan

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