CVE-2021-40830: amazon web services aws iot device sdk v2 for c++ Improper Certificate Validation
Vulnerability summary
CVE-2021-40830 is a high (CVSS 8.8) Improper Certificate Validation vulnerability in amazon web services aws iot device sdk v2 for c++. EPSS estimates a 0.39% chance of exploitation in the next 30 days, higher than 31.2% of scored vulnerabilities.
Timeline
- 22-11-2021PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
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.
CVSS metrics
9 scores · 5 sources · 3 versions- OSV · NpmEcosystem advisory · calculated7.3HighCVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- OSV · MavenEcosystem advisory · calculated7.3HighCVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CVE.orgCNA6.3MediumCVSS:3.1/AV:A/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:HDiffers
- OSV · PypiEcosystem advisory · calculated6.3MediumCVSS:3.1/AV:A/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:HDiffers
- OSV · NpmEcosystem advisory · calculated6.3MediumCVSS:3.1/AV:A/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:HDiffers
- OSV · MavenEcosystem advisory · calculated6.3MediumCVSS:3.1/AV:A/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:HDiffers
EPSS trend
Probability
0.39%
Chance of exploitation in the next 30 days
Percentile
31%
Versus all other CVEs
30-day change
0.00 pp
From 0.39% on 18-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Amazon web services5 products
- aws iot device sdk v2 for c++≥ unspecified, < 1.12.7
- aws iot device sdk v2 for java≥ unspecified, < 1.5.0
- aws iot device sdk v2 for node.js≥ unspecified, < 1.5.3
- aws iot device sdk v2 for python≥ unspecified, < 1.6.1
- aws-c-io0.10.4
Amazon2 products
- amazon_web_services_aws-c-io0.10.4
- amazon_web_services_internet_of_things_device_software_development_kit_v2< 1.5.0 | < 1.5.3 | < 1.6.1 | < 1.12.7
Npm1 product
- aws-iot-device-sdk-v2< 1.5.3
PyPI1 product
- awsiotsdk< 1.6.1
Software.amazon.awssdk.iotdevicesdk1 product
- aws-iot-device-sdk< 1.5.0
5 vendors · 10 products
