CVE-2025-52870
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA buffer overflow 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 ( 2026/01/20 ) and later
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceA buffer overflow vulnerability exists in Qsync Central that allows an authenticated remote attacker to modify memory contents or crash processes. The CVSS 8.1 indicates high exploitability and impact. The attacker first requires valid user credentials to exploit this vulnerability.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data>= 5.0.0.0, < 5.0.0.4CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Verify Qsync Central is installedAccess the QNAP device administration interface and navigate to the Qsync Central application page, or use the QNAP CLI tool to list installed packages.Affected if Qsync Central is not present on the system, the vulnerability does not apply.
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Determine the Qsync Central versionIn the Qsync Central web interface, locate the version information typically found in the About or Settings section. Alternatively, use the QNAP command line to query the installed package version.Affected if The exact version number cannot be determined, treat the system as potentially vulnerable.
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Compare installed version to affected rangeCheck if the installed version is >= 5.0.0.0 AND < 5.0.0.4. Versions 5.0.0.0 through 5.0.0.3 are affected. Version 5.0.0.4 and later are not vulnerable.Affected if The installed version falls within >= 5.0.0.0 and < 5.0.0.4, the environment is vulnerable.
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Confirm remote authentication is enabledVerify that user authentication is enabled for Qsync Central access, as the attacker requires valid user credentials to exploit this vulnerability.Affected if Remote authentication is disabled and no users can log in, the exploit path is blocked though the vulnerable code still exists.
If Qsync Central is installed and the version is 5.0.0.0 through 5.0.0.3 (any version >= 5.0.0.0 but below 5.0.0.4), the environment is affected by this buffer overflow vulnerability.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped5.0.0.4
Upgrade Qsync Central to version 5.0.0.4 or later. Until upgrade is possible, enforce strict access controls and monitor for suspicious authenticated sessions.
Qsync Central 5.0.0.4
- Identify the current version of Qsync Central installed on the QNAP device
- Schedule a maintenance window for the upgrade process
- Back up any critical data and configurations as a precautionary measure
- Access the QNAP admin interface (QTS or QuTS hero)
- Navigate to the Qsync Central application management area
- Upgrade Qsync Central to version 5.0.0.4 or later (released 2026/01/20)
- Verify the upgrade was successful by checking the installed version
- Confirm that Qsync Central services are running normally
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation2.0 h
- Testing6.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-52870 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-52870 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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