CVE-2025-67433
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 heap buffer overflow in the processRequest function of Open TFTP Server MultiThreaded v1.7 allows attackers to cause a Denial of Service (DoS) via a crafted DATA packet.
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 heap buffer overflow vulnerability exists in the processRequest function of Open TFTP Server MultiThreaded v1.7. Attackers can trigger the overflow by sending specially crafted DATA packets, leading to denial of service.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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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Confirm Open TFTP Server MultiThreaded is installedCheck for the presence of the TFTP server executable or service on the system. On Windows, look for tftp-server.exe or similar in program directories or run 'sc query' to list services. On Linux, check for tftp-related packages or processes.Affected if The software is present and running on the system
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Verify the installed version is 1.7Run the TFTP server executable with a version flag (such as -v, -version, or --version) or check the file properties. Compare the version string to '1.7'.Affected if The installed version is exactly 1.7 (or falls within the 1.7.x release line if other 1.7 variants exist)
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Confirm the TFTP service is listening on the networkRun 'netstat -an | grep 69' or 'ss -ulnp | grep :69' to check if UDP port 69 (the TFTP default port) is open and listening. Verify the process is bound to a network interface rather than localhost only.Affected if The TFTP server is bound to a reachable network interface on UDP port 69
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Check for unexpected TFTP traffic or service degradationMonitor TFTP server logs for crash events, error messages related to processRequest function, or unusual patterns in DATA packet handling. Review system event logs for service restart events.Affected if The server has crashed or exhibited instability related to DATA packet processing
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Assess network exposure of the TFTP serviceDetermine if the TFTP server is accessible from untrusted networks by reviewing firewall rules, router configurations, or network ACLs. Check if the server is exposed to the internet or guest networks.Affected if The TFTP port is accessible from networks without explicit authorization
A user is affected if Open TFTP Server MultiThreaded version 1.7 is installed, the TFTP service is running and network-accessible, and the system has not been patched to address the heap buffer overflow in processRequest function.
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 patches if available; otherwise, implement network-level access controls to restrict TFTP traffic to authorized sources and consider disabling the TFTP server until a fix can be deployed.
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-67433 — 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-2025-67433 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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