CVE-2021-22636
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 · uneditedTexas Instruments TI-RTOS, when configured to use HeapMem heap(default), malloc returns a valid pointer to a small buffer on extremely large values, which can trigger an integer overflow vulnerability in 'HeapMem_allocUnprotected' and result in code 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 · moderate confidenceInteger overflow vulnerability in TI-RTOS HeapMem_allocUnprotected function. When HeapMem heap (the default configuration) processes malloc requests with extremely large values, an integer overflow occurs causing malloc to return a valid pointer to a small buffer instead of failing, leading to potential 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 dataall versions< 4.40.00< 4.40.00< 4.10.03all versionsall versionsCVSS 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
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/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 TI-RTOS or SDK version in useLocate the firmware image, project documentation, or build artifacts and check the embedded TI-RTOS or Simplelink SDK version string or release notesAffected if The version is TI-RTOS all versions, Simplelink CC13xx SDK < 4.40.00, Simplelink CC26xx SDK < 4.40.00, Simplelink CC32xx SDK < 4.10.03, or Simplelink MSP432e401y/MSP432e411y all versions
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Verify HeapMem module is in useInspect the TI-RTOS configuration file (usually a .cfg file) or the generated kernel/heap initialization code for references to HeapMem or HeapMem_allocUnprotectedAffected if HeapMem is configured as the default heap allocator in the TI-RTOS kernel configuration
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Inspect HeapMem_allocUnprotected source codeLocate the HeapMem_allocUnprotected function in the TI-RTOS source files (typically in the HeapMem module) and examine the allocation size calculation logic for integer overflow checksAffected if The function lacks proper bounds checking on the requested allocation size before performing arithmetic that could overflow
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Check for large allocation requests in firmware codeSearch firmware source code for malloc, HeapMem_alloc, or HeapMem_allocUnprotected calls that pass user-controlled or unbounded size values without prior validationAffected if The firmware performs heap allocations with size parameters that could exceed the maximum representable value for the arithmetic in the vulnerable function
If the deployed TI-RTOS or Simplelink SDK version falls within the affected ranges AND uses the default HeapMem allocator, the environment is likely vulnerable to the integer overflow.
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 · scoped4.10.034.40.00
Implement proper bounds checking in HeapMem_allocUnprotected to validate allocation requests and prevent integer overflows before computing buffer sizes. Consider using a safer heap implementation or adding allocation size validation.
Simplelink CC13xx SDK 4.40.00 / CC26xx SDK 4.40.00 / CC32xx SDK 4.10.03 (or later)
- 1. Identify which TI Simplelink SDK variant is in use (CC13xx, CC26xx, or CC32xx)
- 2. For CC13xx SDK: upgrade to version 4.40.00 or later from TI's software download repository
- 3. For CC26xx SDK: upgrade to version 4.40.00 or later from TI's software download repository
- 4. For CC32xx SDK: upgrade to version 4.10.03 or later from TI's software download repository
- 5. For TI-RTOS kernel: verify if the SDK upgrade includes the fixed HeapMem module; if not, obtain the fixed HeapMem.c/HeapMem.h from TI's patch release
- 6. Rebuild and redeploy the firmware with the updated SDK/RTOS components
- 7. Test the allocation paths that handle user-controlled sizes to confirm the integer overflow cannot occur
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing12.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-22636 — 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-2021-22636 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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