NuttxApplication · Apache
CVE-2021-26461
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 · uneditedApache Nuttx Versions prior to 10.1.0 are vulnerable to integer wrap-around in functions malloc, realloc and memalign. This improper memory assignment can lead to arbitrary memory allocation, resulting in unexpected behavior such as a crash or a remote code injection/execution.
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 · high confidenceApache Nuttx versions prior to 10.1.0 contain an integer wrap-around (integer overflow) vulnerability in the memory allocation functions malloc, realloc, and memalign. This flaw allows improper memory assignment where the size calculation overflows, enabling attackers to trigger arbitrary memory allocation at controlled addresses, leading to potential crashes or remote code execution.
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
NuttxApplication
< 10.1.0CVSS 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 Apache Nuttx installationDetermine if your system or application is running Apache Nuttx. This is typically an embedded OS, so check firmware images, build configurations, or system documentation for 'Nuttx' references.Affected if Apache Nuttx is present in the environment
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Determine installed Nuttx versionLocate and read the Nuttx version identifier in your build system, firmware header, or version file. Common locations include the build configuration, README files within the Nuttx source tree, or the system boot banner.Affected if The version is below 10.1.0 (e.g., 10.0.x, 9.x, or any version number less than 10.1.0)
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Identify use of vulnerable allocation functionsSearch the application or system code for calls to malloc, realloc, or memalign where the size argument could be user-controlled or derived from external input. Review source code or binary analysis for these function calls.Affected if The code uses malloc, realloc, or memalign with size values that can be influenced by external input
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Check for size calculation patterns that could overflowExamine code that calculates memory allocation sizes, looking for arithmetic operations (especially addition or multiplication) on size values before passing them to allocation functions. Look for patterns where large inputs or multiple size parameters are combined.Affected if Size calculations involve arithmetic that could wrap around to small values, causing undersized memory allocations
You are affected if your system runs Apache Nuttx version below 10.1.0 and your application code passes user-controlled or computed sizes to malloc, realloc, or memalign without proper validation.
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 · scoped10.1.0
Upgrade Apache Nuttx to version 10.1.0 or later which contains the fix for the integer wrap-around vulnerability in the memory allocation functions.
10.1.0
- 1. Backup your current Nuttx implementation and configuration
- 2. Obtain Apache Nuttx version 10.1.0 or later from the official Apache Nuttx repository (https://nuttx.apache.org/)
- 3. Review the release notes for version 10.1.0 to understand any changes relevant to your implementation
- 4. Update your project's dependency configuration to specify Nuttx version 10.1.0 or later
- 5. Rebuild your Nuttx-based application with the updated version
- 6. Test the rebuilt application to verify functionality remains intact
- 7. Deploy the updated application
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Nuttx
Scoped from the published advisory
- Consultation3.0 h
- Implementation6.0 h
- Testing8.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,472.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-26461 — 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-2021-26461 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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