CVE-2021-40830

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.