CVE-2021-34809

Name: CVE-2021-34809
Creator: NVD / NIST
Published: 2021-06-18T03:15:06.807+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 1.93%

Last modified Jun 17, 2026

CVE-2021-34809 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. Improper neutralization of special elements used in a command ('Command Injection') vulnerability in task management component in Synology Download Station before 3.8.16-3566 allows remote authenticated users to execute arbitrary code via unspecified vectors.. EPSS estimates a 1.93% chance of exploitation in the next 30 days.

Description

Improper neutralization of special elements used in a command ('Command Injection') vulnerability in task management component in Synology Download Station before 3.8.16-3566 allows remote authenticated users to execute arbitrary code via unspecified vectors.

Metrics

CVSS 3.1

8.8/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

1.93%

77.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-77

Affected Software

Vendor	Product	Versions
Synology	Download Station	< 3.8.16-3566

References

https://www.synology.com/security/advisory/Synology_SA_21_11Vendor Advisory
https://www.synology.com/security/advisory/Synology_SA_21_11Vendor Advisory

Timeline

Published: Jun 18, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-34809?

How severe is CVE-2021-34809?

CVE-2021-34809 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 1.93% probability of exploitation in the next 30 days.

How do I fix CVE-2021-34809?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-34809?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST