CVE intelligence and bounded remediation

CVE-2021-34810 — Synology Download Station security vulnerability

Critical CVSS 9.9

Improper privilege management vulnerability in cgi component in Synology Download Station before 3.8.16-3566 allows remote authenticated users to execute arbitrary code via unspecified vectors.

Severity
Critical
CVSS
9.9 (3.1)
Published
2021-06-18
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-269

Affected products

  • synology / download_station

Matched remediation archetype

Privilege escalation and unsafe privilege management

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

Check exposure

  • Map service accounts, operating-system identities, roles, capabilities, impersonation, set-user transitions, and administrative helper paths.
  • Determine whether untrusted users or lower-privilege processes can reach the affected transition or modify inputs it trusts.
  • Review file, socket, registry, device, job, container, and cloud-role permissions used before and after privilege changes.

Remediate safely

  • Apply the supported fix and redesign privileged operations as a minimal, authenticated, allowlisted interface.
  • Drop privileges before processing untrusted input, verify the drop succeeds, and remove unnecessary roles, capabilities, and write permissions.
  • Validate ownership and permissions at time of use and add explicit lower-to-higher privilege boundary tests.

Authoritative sources

Complete CVE record and remediation plan

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