CVE-2025-50402
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 · uneditedFAST FAC1200R F400_FAC1200R_Q is vulnerable to Buffer Overflow in the function sub_80435780 via the parameter string fac_password.
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 the FAST FAC1200R F400_FAC1200R_Q router firmware. The vulnerability is located in function sub_80435780 and can be triggered through the fac_password parameter, potentially allowing remote code execution or denial of service.
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= f400_fac1200r_qCVSS 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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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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Identify the device modelAccess the router web interface or check the device label/marketing to confirm it is a Fastcom Fac1200r router (model F400_FAC1200R_Q)Affected if The device is not a Fastcom Fac1200r F400_FAC1200R_Q model - not affected
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Check the installed firmware versionLog into the router web interface and navigate to the firmware/version information page, or use SNMP/CLI to query the firmware version stringAffected if Firmware version equals f400_fac1200r_q - affected
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Verify the web management interface is accessibleAttempt to access the router web interface over HTTP/HTTPS from a network location - the fac_password parameter is submitted via HTTP POST to the web interfaceAffected if Web interface is not exposed or not accessible - less likely to be exploitable
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Check if remote management is enabledIn the router web interface, look for remote management settings (often under Administration or System settings) to see if HTTP/HTTPS management is allowed from WAN interfacesAffected if Remote management is enabled and the web interface is WAN-accessible - higher exposure risk
The environment is affected if the device is a Fastcom Fac1200r F400_FAC1200R_Q running firmware version f400_fac1200r_q and the web interface with the fac_password parameter is accessible.
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.
From vendor dataApply vendor-supplied firmware updates when available. If no update exists, consider network segmentation to limit exposure of the affected device and implement input validation at upstream network devices.
- Consultation8.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-50402 — 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-2025-50402 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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