CVE-2025-30269
Qnap Qsync Central 5.0.0.0 – 5.0.0.4
Raw vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XSummary
CVE-2025-30269 is a low-severity Use of Externally-Controlled Format String (CWE-134) vulnerability in Qnap Qsync Central. Its CVSS base score is 0.6 (Low).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 20th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2025-30269 is a use of externally-controlled format string vulnerability (CWE-134) affecting Qsync Central. Published on 2026-02-11, it carries a CVSS v3.1 base score of 8.1 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N), indicating high severity due to network accessibility, low attack complexity, and significant impacts on confidentiality and integrity.
A remote attacker who has gained a user account on the affected system can exploit the vulnerability to obtain secret data or modify memory. The low privilege requirement (PR:L) means legitimate user credentials suffice for exploitation, enabling unauthorized data disclosure or memory corruption without user interaction.
QNAP has fixed the vulnerability in Qsync Central version 5.0.0.4, released on 2026/01/20, and later versions. Additional mitigation details are available in the security advisory at https://www.qnap.com/en/security-advisory/qsa-26-02.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-207456
Vulnerability Data
A use of externally-controlled format string vulnerability has been reported to affect Qsync Central. If a remote attacker gains a user account, they can then exploit the vulnerability to obtain secret data or modify memory. We have already fixed the…
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vulnerability in the following version: Qsync Central 5.0.0.4 ( 2026/01/20 ) and later
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and static analysis can discover format-string vulnerabilities before deployment.
Input validation can reject or sanitize externally supplied format strings before they reach formatting functions.
Secure development standards and tools can mandate use of static format strings or safe formatting APIs.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development can detect format-string vulnerabilities before release.
Secure SDLC mandates input validation and safe API usage that can prevent externally-controlled format strings.
Application security requirements can specify safe formatting functions and ban uncontrolled format strings.
Secure architecture principles discourage dangerous string-handling patterns that lead to format-string issues.
Secure coding standards directly forbid the use of untrusted format strings and prescribe safe alternatives.