CVE-2025-66592
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 · uneditedAn origin validation error vulnerability in Synology Active Backup for Business Agent before 3.1.0-4967 allows local users to write arbitrary files with restricted content and conduct denial-of-service during installation.
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 confidenceAn origin validation error in Synology Active Backup for Business Agent before version 3.1.0-4967 allows local users to write arbitrary files with restricted content and cause denial-of-service during the installation process. This is a local privilege escalation and file write vulnerability affecting the agent installer.
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< 3.1.0-4967CVSS 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
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- Low
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:L/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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Locate the Synology Active Backup for Business Agent installationSearch for the agent installation directory or check common program installation locations on the system where the agent may be installedAffected if The agent is found installed on the system
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Retrieve the installed version of the agentAccess the version information of the installed agent - this is typically available in the program files directory, installer logs, or system registry entries related to the applicationAffected if The version cannot be determined or the agent is installed without version metadata
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Compare the installed version against 3.1.0-4967Check if the installed version is lower than 3.1.0-4967 - ensure the full four-part version number is compared correctlyAffected if The installed version is less than 3.1.0-4967 (for example, 3.1.0-4000, 3.0.5-2000, or any version starting with numbers lower than 4967 in the third segment)
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Verify the installer was run on this systemCheck installation logs, event logs, or the presence of the agent service to confirm the agent installer was executed on this machineAffected if The agent installer has been run and the agent is present
A user is affected if Synology Active Backup for Business Agent is installed with a version number lower than 3.1.0-4967, indicating the vulnerable installer was used.
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 · scoped3.1.0-4967
Update Synology Active Backup for Business Agent to version 3.1.0-4967 or later to address the origin validation error.
Active Backup For Business Agent 3.1.0-4967
- Identify the current installed version of Synology Active Backup for Business Agent
- Backup any critical data protected by the current installation
- Uninstall the current version of Active Backup For Business Agent if already installed
- Download Active Backup For Business Agent version 3.1.0-4967 or later from the Synology download center
- Install the updated version following Synology's standard installation procedures
- Verify the installation completed successfully and the version is correct
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,744.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-66592 — 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-2025-66592 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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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- 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
- No spam, self-promotion, credentials, or personal data