CVE-2021-40829
HIGHCVE-2021-40829 is a high-severity (CVSS 8.8) CWE-295 vulnerability in software.amazon.awssdk.iotdevicesdk:aws-iot-device-sdk. O3 Security confirms whether CVE-2021-40829 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Improper certificate management in AWS IoT Device SDK v2
Real-World Exposure
software.amazon.awssdk.iotdevicesdk:aws-iot-device-sdk📦aws-iot-device-sdk-v2🐍awsiotsdkReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven, npm, PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Connections initialized by the AWS IoT Device SDK v2 for Java (versions prior to 1.4.2), Python (versions prior to 1.6.1), C++ (versions prior to 1.12.7) and Node.js (versions prior to 1.5.3) did not verify server certificate hostname during TLS handshake when overriding Certificate Authorities (CA) in their trust stores on MacOS. This issue has been addressed in aws-c-io submodule versions 0.10.5 onward. This issue affects: Amazon Web Services AWS IoT Device SDK v2 for Java versions prior to 1.4.2 on macOS. Amazon Web Services AWS IoT Device SDK v2 for Python versions prior to 1.6.1 on macOS. Amazon Web Services AWS IoT Device SDK v2 for C++ versions prior to 1.12.7 on macOS. Amazon Web Services AWS IoT Device SDK v2 for Node.js versions prior to 1.5.3 on macOS. Amazon Web Services AWS-C-IO 0.10.4 on macOS.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | software.amazon.awssdk.iotdevicesdk:aws-iot-device-sdk | all versions | 1.4.2 |
| 📦npm | aws-iot-device-sdk-v2 | all versions | 1.5.3 |
| 🐍PyPI | awsiotsdk | all versions | 1.6.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for software.amazon.awssdk.iotdevicesdk:aws-iot-device-sdk. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update software.amazon.awssdk.iotdevicesdk:aws-iot-device-sdk to 1.4.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-40829 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2021-40829 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2021-40829. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2021-40829 in your dependencies?
O3 detects CVE-2021-40829 across Maven, npm, PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.