CVE-2021-40828 json
TLS hostname validation issues within AWS IoT Device SDKs on Windows
published 2021-11-22 4 y ago modified 2026-06-17 4 mo ago also GHSA-94jq-q5v2-76wj , PYSEC-2021-861 , EUVD-2021-0028
- cvss
- 6.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 35%
- public exploits
- 0
- none known
Summary
Connections initialized by the AWS IoT Device SDK v2 for Java (versions prior to 1.3.3), Python (versions prior to 1.5.18), C++ (versions prior to 1.12.7) and Node.js (versions prior to 1.5.1) did not verify server certificate hostname during TLS handshake when overriding Certificate Authorities (CA) in their trust stores on Windows. This issue has been addressed in aws-c-io submodule versions 0.9.13 onward. This issue affects: Amazon Web Services AWS IoT Device SDK v2 for Java versions prior to 1.3.3 on Microsoft Windows. Amazon Web Services AWS IoT Device SDK v2 for Python versions prior to 1.5.18 on Microsoft Windows. Amazon Web Services AWS IoT Device SDK v2 for C++ versions prior to 1.12.7 on Microsoft Windows. Amazon Web Services AWS IoT Device SDK v2 for Node.js versions prior to 1.5.3 on Microsoft Windows.
Patch / fix
- maven software.amazon.awssdk.iotdevicesdk:aws-iot-device-sdk 1.3.3
- npm aws-iot-device-sdk-v2 1.5.1
- pypi awsiotsdk 1.5.18
- Amazon Web Services AWS IoT Device SDK v2 for Java 1.3.3
- Amazon Web Services AWS IoT Device SDK v2 for Python 1.5.18
- Amazon Web Services AWS IoT Device SDK v2 for C++ 1.12.7
- Amazon Web Services AWS IoT Device SDK v2 for Node.js 1.5.3
Exploit prediction
0.41% chance of exploitation in the next 30 days, higher than 35% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.3 | CVSS:3.1/AV:A/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:H |
| NVD | 3.1 | 8.8 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 5.8 | AV:A/AC:L/Au:N/C:P/I:P/A:P |
| GitHub | 3.1 | 6.3 | CVSS:3.1/AV:A/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| maven | software.amazon.awssdk.iotdevicesdk:aws-iot-device-sdk | <1.3.3 |
1.3.3 |
| npm | aws-iot-device-sdk-v2 | <1.5.1 |
1.5.1 |
| pypi | awsiotsdk | <1.5.18 |
1.5.18 |
Affected products
- Amazon Web Services AWS IoT Device SDK v2 for Java
- Amazon Web Services AWS IoT Device SDK v2 for Python
- Amazon Web Services AWS IoT Device SDK v2 for C++
- Amazon Web Services AWS IoT Device SDK v2 for Node.js
- Amazon Web Services AWS-C-IO
Classification
- Weakness
-
- CWE-295 Improper Certificate Validation
References
-
github.com
/aws/aws-iot-device-sdk-java-v2/commit/67950ad2a02f2f9355c310b69dc9226b017f32f2
web
-
github.com
/aws/aws-iot-device-sdk-js-v2/commit/4be41394f1aee979e6f4b012fcb01eecabd0c08d
web
-
github.com
/aws/aws-iot-device-sdk-python-v2/commit/fd4c0ba04b35eab9e20c635af5548fcc5a92d8be
web
-
github.com
/awslabs/aws-c-io/
product, web
-
github.com
/aws/aws-iot-device-sdk-cpp-v2
web, product
-
github.com
/aws/aws-iot-device-sdk-python-v2
web, product
-
github.com
/aws/aws-iot-device-sdk-java-v2
web, product
-
github.com
/aws/aws-iot-device-sdk-js-v2
web, product
-
nvd.nist.gov
/vuln/detail/CVE-2021-40828
advisory
-
github.com
/advisories/GHSA-94jq-q5v2-76wj
advisory
-
github.com
/awslabs/aws-c-io
web
-
github.com
/pypa/advisory-database/tree/main/vulns/awsiotsdk/PYSEC-2021-861.yaml
web
Sources
- CVE List CVE-2021-40828
- GitHub Advisory GHSA-94jq-q5v2-76wj
- NVD CVE-2021-40828
- OSV PYSEC-2021-861
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.