CVE-2021-40831
6.3 · MEDIUMOverview
CVE-2021-40831 is a medium-severity vulnerability affecting amazon amazon_web_services_aws-c-io. It was published on November 23, 2021 and has a CVSS 3.1 base score of 6.3 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 6.3, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
Technical 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 macOS systems. Additionally, SNI validation is also not enabled when the CA has been “overridden”. 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-
Remediation
Check the references section for vendor advisories and patches from amazon. Update amazon_web_services_aws-c-io to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| amazon | amazon_web_services_internet_of_things_device_software_development_kit_v2 | >= 0, < 1.5.0 | Affected |
References
Frequently Asked Questions
What is CVE-2021-40831?
CVE-2021-40831 is a medium-severity vulnerability affecting amazon amazon_web_services_aws-c-io. It was published on November 23, 2021 and has a CVSS 3.1 base score of 6.3 (MEDIUM).
How severe is CVE-2021-40831?
This vulnerability has a CVSS 3.1 base score of 6.3, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2021-40831?
Check the references section for vendor advisories and patches from amazon. Update amazon_web_services_aws-c-io to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-40831?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-40831 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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