CVE-2025-5867
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 vulnerability classified as critical was found in RT-Thread 5.1.0. This vulnerability affects the function csys_sendto of the file rt-thread/components/lwp/lwp_syscall.c. The manipulation of the argument to leads to null pointer dereference.
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 null pointer dereference vulnerability exists in RT-Thread 5.1.0 within the csys_sendto function in the LWP (LightWeight Process) syscall layer. By manipulating the argument passed to this function, an attacker can cause the code to dereference a null pointer, leading to a denial of service or potentially arbitrary code execution given the critical CVSS score.
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= 5.1.0CVSS 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 RT-Thread versionCheck the RT-Thread version by examining the build configuration (Kconfig), version header files (rt_version.h), or by calling rt_version() at runtime if the system provides a shell or debug interfaceAffected if The installed version is exactly 5.1.0
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Verify LWP syscall layer is enabledCheck the RT-Thread configuration (usually in .config or via menuconfig) for LWP (LightWeight Process) support being enabled. This is typically found under the kernel or filesystem configuration optionsAffected if LWP support is enabled in the build configuration
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Check for csys_sendto usageReview the system or application code to determine if the csys_sendto syscall function is being invoked. This can be done by searching for calls to this function or checking if network socket operations go through the LWP layerAffected if The csys_sendto function is being called with user-controlled arguments without prior null pointer validation
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Inspect syscall argument handlingExamine the code path leading to csys_sendto to see if argument pointers are validated before being passed. Look for direct dereferencing of the address argument without null checksAffected if The code dereferences the address argument in csys_sendto without verifying it is non-null first
You are affected if you are running RT-Thread version 5.1.0 with the LWP syscall layer enabled and the csys_sendto function is being used with potentially unvalidated pointer arguments.
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 a patch that adds proper null pointer validation in the csys_sendto function before dereferencing the argument pointer, and validate all pointer inputs from userspace. Consider updating to a patched version of RT-Thread if available.
- Consultation2.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,808.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-5867 — 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-2025-5867 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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- Version or environment caveats, and links to real fixes
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