CVE-2021-34811

Severity: medium (CVSS 4.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-06-18 · updated 2026-06-17
Weakness: CWE-918

Description

Server-Side Request Forgery (SSRF) vulnerability in task management component in Synology Download Station before 3.8.16-3566 allows remote authenticated users to access intranet resources via unspecified vectors.

Affected products

Synology Download Station: before 3.8.16-3566 — fixed in 3.8.16-3566

How to fix

Upgrade to a fixed version: Synology Download Station 3.8.16-3566. Check the vendor advisory for mitigations.

References

https://www.synology.com/security/advisory/Synology_SA_21_11
https://www.synology.com/security/advisory/Synology_SA_21_11

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