CVE-2021-38687
Stack Overflow Vulnerability in Surveillance Station
A stack buffer overflow vulnerability has been reported to affect QNAP NAS running Surveillance Station. If exploited, this vulnerability allows attackers to execute arbitrary code. We have already fixed this vulnerability in the following versions of Surveillance Station: QTS 5.0.0 (64 bit): Surveillance Station 5.2.0.4.2 ( 2021/10/26 ) and later QTS 5.0.0 (32 bit): Surveillance Station 5.2.0.3.2 ( 2021/10/26 ) and later QTS 4.3.6 (64 bit): Surveillance Station 5.1.5.4.6 ( 2021/10/26 ) and later QTS 4.3.6 (32 bit): Surveillance Station 5.1.5.3.6 ( 2021/10/26 ) and later QTS 4.3.3: Surveillance Station 5.1.5.3.6 ( 2021/10/26 ) and later
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Stack Overflow Vulnerability in Surveillance Station
A stack buffer overflow vulnerability has been reported to affect QNAP NAS running Surveillance Station. If exploited, this vulnerability allows attackers to execute arbitrary code. We have already fixed this vulnerability in the following versions of Surveillance Station: QTS 5.0.0 (64 bit): Surveillance Station 5.2.0.4.2 ( 2021/10/26 ) and later QTS 5.0.0 (32 bit): Surveillance Station 5.2.0.3.2 ( 2021/10/26 ) and later QTS 4.3.6 (64 bit): Surveillance Station 5.1.5.4.6 ( 2021/10/26 ) and later QTS 4.3.6 (32 bit): Surveillance Station 5.1.5.3.6 ( 2021/10/26 ) and later QTS 4.3.3: Surveillance Station 5.1.5.3.6 ( 2021/10/26 ) and later
- Record
CVE-2021-38687- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-120
- Updated
- 2026-11-02
EUVDEUVD-2021-25126
A stack buffer overflow vulnerability has been reported to affect QNAP NAS running Surveillance Station. If exploited, this vulnerability allows attackers to execute arbitrary code. We have already fixed this vulnerability in the following versions of Surveillance Station: QTS 5.0.0 (64 bit): Surveillance Station 5.2.0.4.2 ( 2021/10/26 ) and later QTS 5.0.0 (32 bit): Surveillance Station 5.2.0.3.2 ( 2021/10/26 ) and later QTS 4.3.6 (64 bit): Surveillance Station 5.1.5.4.6 ( 2021/10/26 ) and later QTS 4.3.6 (32 bit): Surveillance Station 5.1.5.3.6 ( 2021/10/26 ) and later QTS 4.3.3: Surveillance Station 5.1.5.3.6 ( 2021/10/26 ) and later
- Record
EUVD-2021-25126- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-8397-33w7-cmhc No score
A stack buffer overflow vulnerability has been reported to affect QNAP NAS running Surveillance...
A stack buffer overflow vulnerability has been reported to affect QNAP NAS running Surveillance Station. If exploited, this vulnerability allows attackers to execute arbitrary code. We have already fixed this vulnerability in the following versions of Surveillance Station: QTS 5.0.0 (64 bit): Surveillance Station 5.2.0.4.2 ( 2021/10/26 ) and later QTS 5.0.0 (32 bit): Surveillance Station 5.2.0.3.2 ( 2021/10/26 ) and later QTS 4.3.6 (64 bit): Surveillance Station 5.1.5.4.6 ( 2021/10/26 ) and later QTS 4.3.6 (32 bit): Surveillance Station 5.1.5.3.6 ( 2021/10/26 ) and later QTS 4.3.3: Surveillance Station 5.1.5.3.6 ( 2021/10/26 ) and later
- Record
GHSA-8397-33w7-cmhc- Weakness
- CWE-120
- Updated
- 2026-11-02
NVD
A stack buffer overflow vulnerability has been reported to affect QNAP NAS running Surveillance Station. If exploited, this vulnerability allows attackers to execute arbitrary code. We have already fixed this vulnerability in the following versions of Surveillance Station: QTS 5.0.0 (64 bit): Surveillance Station 5.2.0.4.2 ( 2021/10/26 ) and later QTS 5.0.0 (32 bit): Surveillance Station 5.2.0.3.2 ( 2021/10/26 ) and later QTS 4.3.6 (64 bit): Surveillance Station 5.1.5.4.6 ( 2021/10/26 ) and later QTS 4.3.6 (32 bit): Surveillance Station 5.1.5.3.6 ( 2021/10/26 ) and later QTS 4.3.3: Surveillance Station 5.1.5.3.6 ( 2021/10/26 ) and later
- Record
CVE-2021-38687- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-120
- 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-2021-38687 is a high vulnerability (CVSS 8.1) in Qnap Surveillance Station, published December 29, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.32%, the 71st percentile. No source names a fixed version.