CVE-2021-34809
Improper neutralization of special elements used in a command ('Command Injection') vulnerability...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
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.
- Record
CVE-2021-34809- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-77
- Updated
- 2026-11-02
EUVDEUVD-2021-21456
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.
- Record
EUVD-2021-21456- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-46j9-2j4r-83q6 No score
Improper neutralization of special elements used in a command ('Command Injection') vulnerability...
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.
- Record
GHSA-46j9-2j4r-83q6- Weakness
- CWE-77
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2021-34809- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 6.5 Medium
AV:N/AC:L/Au:S/C:P/I:P/A:P - Weakness
- CWE-77
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, products, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-34809 is a critical vulnerability (CVSS 9.9) in Qnap Systems Inc. Download Station, published June 18, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.93%, the 80th percentile. No source names a fixed version.