CVE-2025-30273
Published: 29 August 2025
Summary
CVE-2025-30273 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Qnap Qts. Its CVSS base score is 7.1 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 42.7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-16 (Memory Protection) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2025-30273 is an out-of-bounds write vulnerability (CWE-787) affecting several versions of QNAP's QTS and QuTS hero operating systems. Published on 2025-08-29, it carries a CVSS v3.1 base score of 8.1 (AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H), indicating high severity due to its potential for network-based exploitation with low complexity and low privileges required.
A remote attacker who has gained a user account on an affected QNAP device can exploit the vulnerability to modify or corrupt memory. This can result in significant integrity and availability impacts, though confidentiality is not directly affected.
QNAP has fixed the vulnerability in QTS 5.2.5.3145 build 20250526 and later, as well as QuTS hero h5.2.5.3138 build 20250519 and later. Additional details are available in QNAP security advisory QSA-25-21 at https://www.qnap.com/en/security-advisory/qsa-25-21.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-27787
Vulnerability details
An out-of-bounds write vulnerability has been reported to affect several QNAP operating system versions. If a remote attacker gains a user account, they can then exploit the vulnerability to modify or corrupt memory. We have already fixed the vulnerability in…
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the following versions: QTS 5.2.5.3145 build 20250526 and later QuTS hero h5.2.5.3138 build 20250519 and later
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Out-of-bounds write in authenticated network service on QNAP OS directly enables memory corruption exploitable for privilege escalation from a low-privileged account.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly mitigates the CVE by requiring timely remediation through patching to the fixed QNAP OS versions, eliminating the out-of-bounds write vulnerability.
Implements memory protection mechanisms like non-executable memory, address randomization, and write protections to block exploitation of out-of-bounds writes that corrupt or modify memory.
Validates and sanitizes inputs to external interfaces, reducing the risk of malformed data triggering the out-of-bounds write in authenticated remote sessions.