Vulnerability · Published Nov 22, 2021 · Assigned by F-SecureUS
CVE-2021-40830Inconsistent CA override function behavior within AWS IoT Device SDKs on Unix systems
Medium 6.3
In plain English
A medium-severity security flaw in AWS-C-IO from Amazon Web Services. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
The AWS IoT Device SDK v2 for Java, Python, C++ and Node.js appends a user supplied Certificate Authority (CA) to the root CAs instead of overriding it on Unix systems. TLS handshakes will thus succeed if the peer can be verified either from the user-supplied CA or the system’s default trust-store. Attackers with access to a host’s trust stores or are able to compromise a certificate authority already in the host's trust store (note: the attacker must also be able to spoof DNS in this case) may be able to use this issue to bypass CA pinning. An attacker could then spoof the MQTT broker, and either drop traffic and/or respond with the attacker's data, but they would not be able to forward this data on to the MQTT broker because the attacker would still need the user's private keys to authenticate against the MQTT broker. The 'aws_tls_ctx_options_override_default_trust_store_*' function within the aws-c-io submodule has been updated to override the default trust store. This corrects this issue. This issue affects: Amazon Web Services AWS IoT Device SDK v2 for Java versions prior to 1.5.0 on Linux/Unix. Amazon Web Services AWS IoT Device SDK v2 for Python versions prior to 1.6.1 on Linux/Unix. Amazon Web Services AWS IoT Device SDK v2 for C++ versions prior to 1.12.7 on Linux/Unix. Amazon Web Services AWS IoT Device SDK v2 for Node.js versions prior to 1.5.3 on Linux/Unix. Amazon Web Services AWS-C-IO 0.10.4 on Linux/Unix.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Maven | software.amazon.awssdk.iotdevicesdk:aws-iot-device-sdk | 1.5.0 | GHSA-c4rh-4376-gff4 |
| PyPI | awsiotsdk | 1.6.1 | GHSA-c4rh-4376-gff4 |
| PyPI | awsiotsdk | 1.6.1 | PYSEC-2021-863 |
| npm | aws-iot-device-sdk-v2 | 1.5.3 | GHSA-c4rh-4376-gff4 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Amazon Web Services | AWS IoT Device SDK v2 for Java | unspecified – before 1.5.0 |
| Amazon Web Services | AWS IoT Device SDK v2 for Python | unspecified – before 1.6.1 |
| Amazon Web Services | AWS IoT Device SDK v2 for C++ | unspecified – before 1.12.7 |
| Amazon Web Services | AWS IoT Device SDK v2 for Node.js | unspecified – before 1.5.3 |
| Amazon Web Services | AWS-C-IO | 0.10.4 |
References
- https://github.com/awslabs/aws-c-io/ x_refsource_MISC
- https://github.com/aws/aws-iot-device-sdk-cpp-v2 x_refsource_MISC
- https://github.com/aws/aws-iot-device-sdk-python-v2 x_refsource_MISC
- https://github.com/aws/aws-iot-device-sdk-java-v2 x_refsource_MISC
- https://github.com/aws/aws-iot-device-sdk-js-v2 x_refsource_MISC