Stack-based buffer overflow in QNAP Qsync Central
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
QNAP Qsync Central versions from 5.0.x before 5.0.0.4 contain a buffer copy without checking size of input (CWE-120) in qsyncsrv.cgi. A remote attacker who has gained a user account can exploit this flaw to modify memory or crash processes.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
A buffer copy without checking size of input vulnerability has been reported to affect Qsync Central. If a remote attacker gains a user account, they can then exploit the vulnerability to modify memory or crash processes. We have already fixed the vulnerability in the following version: Qsync Central 5.0.0.4 and later
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Update QNAP Qsync Central to version 5.0.0.4 or later.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
- Fix · CNA Qsync Central (QNAP Systems Inc.) Fixed in 5.0.0.4
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
QNAP Systems Qsync Central 5.0.0.4
3 records Highest priority Priority LOW 3 LOW
Other records, highest priority first
- TI-2025-43916 NULL pointer dereference in QNAP Qsync Central qsyncsrv.cgiPriority LOW 12
- TI-2025-43915 Qsync Central NULL pointer dereference allows denial of servicePriority LOW 12
Timeline
- 2026-10-15 Threatist record created from CVE-2025-29897
- 2026-10-16 Alias added: GHSA-9ww8-86rx-gwm9
- 2026-10-16 CISA SSVC decision points changed
References
More QNAP vulnerabilities
- TI-2022-10581 DeadBolt Ransomware KEVCVSS 3.1CRITICAL 10.0
- TI-2021-09791 Improper Authorization Vulnerability in HBS 3 (Hybrid Backup Sync) KEVCVSS 3.1CRITICAL 10.0
- TI-2020-02221 Command Injection Vulnerability in QTS and QuTS hero KEVCVSS 3.1CRITICAL 9.8
- TI-2019-05103 Path traversal in QNAP NAS devices running Photo Station KEVCVSS 3.1CRITICAL 9.8
- TI-2019-05102 Path traversal in QNAP NAS devices running Photo Station KEVCVSS 3.1CRITICAL 9.8
- TI-2019-05101 Improper input validation in QNAP NAS devices KEVCVSS 3.1CRITICAL 9.8
Sources
- CVE-2025-29897 · CVE Program
- CVE-2025-29897 · NVD
- FIRST EPSS
- GHSA-9ww8-86rx-gwm9 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences