CVE-2025-53591
Qnap Quts Hero h5.2.0.2737 … h5.3.0.3192
Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/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-2025-53591 is a low-severity Use of Externally-Controlled Format String (CWE-134) vulnerability in Qnap Quts Hero. Its CVSS base score is 1.2 (Low).
Operationally, ranked at the 21th 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 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation) — see the control section below for these in your framework.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-0681
Vulnerability Data
A use of externally-controlled format string vulnerability has been reported to affect several QNAP operating system versions. If a remote attacker gains an administrator account, they can then exploit the vulnerability to obtain secret data or modify memory. We have…
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already fixed the vulnerability in the following versions: QTS 5.2.7.3256 build 20250913 and later QuTS hero h5.2.7.3256 build 20250913 and later QuTS hero h5.3.1.3250 build 20250912 and later
- CWE(s)
Related Threats
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
Mitigating Controls (NIST 800-53 r5) AI
Directly blocks externally-controlled format strings (CWE-134) by validating or sanitizing all input before it reaches string-formatting functions.
Requires timely application of the vendor-supplied patches (QTS/QuTS hero 5.2.7/5.3.1 builds listed) that eliminate the vulnerable format-string code paths.
Memory-protection mechanisms limit the ability of a successful format-string exploit to read secrets or corrupt memory even when an administrator account is compromised.
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.