Skip to main content

QNAP QTS CVE-2025-52424

| EUVDEUVD-2025-32469 MEDIUM
NULL Pointer Dereference (CWE-476)
2025-10-03 security@qnapsecurity.com.tw
5.1
CVSS 4.0 · Vendor: qnapsecurity
View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Obtain QNAP admin account
  2. Exploit
    Authenticate to management interface
  3. Execution
    Send crafted request triggering NULL deref
  4. Impact
    Service/device denial of service

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A10:2025 - Mishandling of Exceptional Conditions
ASVS 5.0
V16 - Security Logging and Error Handling Null pointer safety, defensive checks
MITRE ATT&CK

1 technique across 1 tactic: Impact

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Exploitation Conditions

Exploitation requires the attacker to already possess a QNAP administrator account (CVSS PR:H) and network access to the device's management interface (AV:N). The vulnerability affects QTS 5.2.x and QuTS hero h5.2.x builds prior to the 20250715 fix; no special non-default feature toggle is named in the description beyond holding admin privileges. The administrator-credential requirement is the primary limiting factor and sharply reduces realistic risk, since the outcome is only a denial of service (VA:L) against an attacker who already controls the appliance's admin plane.

Impact

This is a genuinely low-priority, high-barrier vulnerability despite its MEDIUM rating. The provided CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:H/UI:N, score 5.1) is internally consistent with the description: PR:H confirms the attacker must already hold an administrator account, and the only impact is VA:L (limited availability loss via DoS) with no confidentiality or integrity impact (VC:N/VI:N). All exploitation signals point the same direction and do not conflict: EPSS is 0.14% (34th percentile), the vulnerability is NOT on CISA KEV, and no public exploit code is referenced. CWE-476 (NULL pointer dereference) aligns with the stated DoS-only outcome. The decisive limiting factor is the administrator-authentication prerequisite - an attacker who already has admin on a QNAP NAS has far more impactful options than crashing a service, which is why real-world exploitation interest is minimal. No SSVC decision data was provided in the input, so an SSVC-based assessment cannot be made. Treat this as routine patch-management, not an emergency.

Exploit ScenarioDerived

An attacker who has already obtained QNAP administrator credentials (via phishing, credential reuse, or a prior compromise) sends a crafted request to a management interface that triggers a NULL pointer dereference, crashing the affected service or the device and causing a denial of service. No public exploit code is identified at time of analysis, and the low availability impact (VA:L) suggests a service interruption rather than full, persistent device takedown.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
Patch available 0.1% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAIv2 – Oct 18, 2026

Authenticated denial of service in QNAP QTS 5.2.x and QuTS hero h5.2.x: a remote attacker who already holds an administrator account on the NAS can trigger a NULL pointer dereference that disrupts service on the appliance. Exploitation requires the highest privilege level (CVSS PR:H) over the network against the management plane, and the resulting impact is limited to availability; there is no confidentiality or integrity loss. QNAP has released fixed builds (QTS 5.2.6.3195 build 20250715 and QuTS hero h5.2.6.3195 build 20250715), EPSS is low at roughly 0.14% (34th percentile), and no public exploit code or confirmed active exploitation was identified at time of analysis.

Earlier versions of this analysis (1)
v1 Mar 13, 2026 - 19:29 CVSS 4.9

RemediationAI

Vendor-released patch: upgrade to QTS 5.2.6.3195 build 20250715 or later, or QuTS hero h5.2.6.3195 build 20250715 or later, following the instructions in QNAP advisory QSA-25-36 (https://www.qnap.com/en/security-advisory/qsa-25-36). Because the prerequisite is a valid administrator account, the highest-value compensating control is credential hygiene: eliminate shared admin accounts, enable MFA where the firmware supports it, and audit accounts with administrative rights, since any such account can already crash the device with or without this CVE. Additionally, remove direct internet exposure of the QTS/QuTS hero management interface (Web Administration on ports 8080/443) by placing it behind a VPN or restricting source IPs at the firewall - this blocks remote (AV:N) reachability, at the cost of requiring VPN access for legitimate administrators. If patching must be deferred, monitor for repeated service restarts or unexpected management-plane crashes as an indicator of attempted exploitation, and consider restricting admin logins to the local subnet, accepting the operational inconvenience of no off-site administration.

Affected VersionsENISA

QTS 5.2.x <5.2.6.3195 build 20250715
QuTS hero h5.2.x <h5.2.6.3195 build 20250715

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

The flaw is a NULL pointer dereference (CWE-476) in the QNAP QTS and QuTS hero operating systems - the embedded Linux-based firmware that runs on QNAP NAS appliances and exposes web-based administrative services. In such a defect, a code path fails to validate a pointer before dereferencing it, causing the process (or potentially the servicing daemon) to crash rather than execute attacker-controlled logic; because the outcome is a crash rather than memory corruption, the practical impact is availability, not code execution. The CPE data enumerates affected QTS 5.2.0.x and 5.2.1.x/5.2.2.x/5.2.3.x firmware builds from 5.2.0.2737 (build 20240417) through 5.2.3.3006 (build 20250108), confirming this is a defect in the 5.2 branch of the firmware rather than a web application plugin. The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:H/UI:N with only VA:L) and our independent CVSS 3.1 assessment (AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L) agree that the attacker must already possess administrative credentials and that only limited availability impact is achievable, which sharply constrains real-world risk.

Severity by source

Vendor (qnapsecurity) PRIMARY 5.1 MEDIUM
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
vuln.today AI 2.7 LOW

Remote reachable (AV:N) but requires an administrator account (PR:H); only a denial-of-service outcome, so A:L with no confidentiality or integrity impact.

3.1 AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L
4.0 AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Primary rating from Vendor (qnapsecurity).

CVSS VectorVendor: qnapsecurity

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
High
User Interaction
None
Vulnerable system: Confidentiality
None
Vulnerable system: Integrity
None
Vulnerable system: Availability
Low
Subsequent system: Confidentiality
None
Subsequent system: Integrity
None
Subsequent system: Availability
None

Lifecycle Timeline

3
CVSS changed
Oct 18, 2026 - 21:38 NVD
4.9 (MEDIUM) 5.1 (MEDIUM)
Patch available
Apr 16, 2026 - 05:29 EUVD
5.2.6.3195
CVE Published
Oct 03, 2025 - 19:15 nvd
MEDIUM 4.9

DescriptionCVE.org

A NULL pointer dereference 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 launch a denial-of-service (DoS) attack.

We have already fixed the vulnerability in the following versions: QTS 5.2.6.3195 build 20250715 and later QuTS hero h5.2.6.3195 build 20250715 and later

Executive ViewAI

Why It Matters

Organizations using A NULL pointer dereference vulnerability should be aware of moderate risk from CVE-2025-52424, a null pointer dereference vulnerability rated CVSS 4.9. Exploitation could compromise the security of affected deployments. Organizations should apply vendor updates when available and monitor for exploitation.

Business Impact: Low
Compensating Controls

Apply vendor patch. If patching is delayed: enable ASLR/DEP, apply network segmentation.

Threat Intelligence Overview

EPSS Score
0.1%
Top 66% exploitable
Prevalence
Medium
QNAP NAS appliances common in SMB and prosumer environments, not ubiquitous
Data Quality
4 sources
Confidence: Medium

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity MEDIUM
CISA KEV No
Public POC No
EPSS 0.1%
Patch available Yes
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Defer
Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
No
Human Impact
Low

Priority Score

26
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +26
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

A null pointer dereference occurs when a program attempts to access memory through a pointer that has been set to NULL (address 0x0).

Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.

More in Qts

View all
CVE-2014-6271 CRITICAL POC
9.8 Sep 24

GNU Bash through 4.3 processes trailing strings after function definitions in the values of environment variables, which

CVE-2014-7169 CRITICAL POC
9.8 Sep 25

GNU Bash through 4.3 bash43-025 processes trailing strings after certain malformed function definitions in the values of

CVE-2017-6361 CRITICAL POC
9.8 Mar 23

QNAP QTS before 4.2.4 Build 20170313 allows attackers to execute arbitrary commands via unspecified vectors. Rated criti

CVE-2017-6360 CRITICAL POC
9.8 Mar 23

QNAP QTS before 4.2.4 Build 20170313 allows attackers to gain administrator privileges and obtain sensitive information

CVE-2017-13067 CRITICAL POC
9.8 Sep 14

QNAP has patched a remote code execution vulnerability affecting the QTS Media Library in all versions prior to QTS 4.2.

CVE-2017-6359 CRITICAL POC
9.8 Mar 23

QNAP QTS before 4.2.4 Build 20170313 allows attackers to gain administrator privileges and execute arbitrary commands vi

CVE-2017-5227 HIGH POC
7.5 Mar 23

QNAP QTS before 4.2.4 Build 20170313 allows local users to obtain sensitive Domain Administrator password information by

CVE-2017-7876 CRITICAL POC
10.0 Jun 15

This command injection vulnerability in QTS allows attackers to run arbitrary commands in the compromised application. R

CVE-2019-7193 CRITICAL POC
9.8 Dec 05

This improper input validation vulnerability allows remote attackers to inject arbitrary code to the system. Rated criti

CVE-2023-39296 HIGH POC
7.5 Jan 05

A prototype pollution vulnerability has been reported to affect several QNAP operating system versions. Rated high sever

CVE-2017-17028 CRITICAL
9.8 Dec 21

A buffer overflow vulnerability in external device function in QNAP QTS version 4.2.6 build 20171026, 4.3.3.0378 build 2

CVE-2017-17033 CRITICAL
9.8 Dec 21

A buffer overflow vulnerability in password function in QNAP QTS version 4.2.6 build 20171026, 4.3.3.0378 build 20171117

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy