CVE intelligence and bounded remediation

CVE-2021-20651 — Elecom File Manager security vulnerability

Critical CVSS 9.1

Directory traversal vulnerability in ELECOM File Manager all versions allows remote attackers to create an arbitrary file or overwrite an existing file in a directory which can be accessed with the application privileges via unspecified vectors.

Severity
Critical
CVSS
9.1 (3.1)
Published
2021-02-12
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-22

Affected products

  • elecom / file_manager

Matched remediation archetype

Path traversal, unsafe upload, and file handling

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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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