CVE intelligence and bounded remediation

CVE-2020-16851 — <p>An elevation of privilege vulnerability exists when the OneDrive for Windows Desktop application improperly handles symbolic links

High CVSS 7.1

<p>An elevation of privilege vulnerability exists when the OneDrive for Windows Desktop application improperly handles symbolic links. An attacker who successfully exploited this vulnerability could overwrite a targeted file with an elevated status.</p> <p>To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application that could exploit the vulnerability and delete a targeted file with an elevated status.</p> <p>The update addresses this vulnerability by correcting where the OneDrive updater performs file writes while running with elevation.</p>

Severity
High
CVSS
7.1 (3.1)
Published
2020-09-11
CISA KEV
Not currently listed
Ecosystem
windows/system
Weaknesses
CWE-59

Affected products

  • microsoft / onedrive

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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