CVE-2021-40830 Inconsistent CA override function behavior within AWS IoT Device SDKs on Unix systems

2021-11-2223:41:18

F-SecureUS

www.cve.org

6.3 Medium

CVSS3

Attack Vector

ADJACENT

Attack Complexity

HIGH

Privileges Required

HIGH

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:A/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:H

8.8 High

AI Score

Confidence

High

0.001 Low

EPSS

Percentile

40.5%

JSON

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.

CNA Affected

[
  {
    "platforms": [
      "Linux/Unix"
    ],
    "product": "AWS IoT Device SDK v2 for Java ",
    "vendor": "Amazon Web Services",
    "versions": [
      {
        "lessThan": "1.5.0",
        "status": "affected",
        "version": "unspecified",
        "versionType": "custom"
      }
    ]
  },
  {
    "platforms": [
      "Linux/Unix"
    ],
    "product": "AWS IoT Device SDK v2 for Python",
    "vendor": "Amazon Web Services",
    "versions": [
      {
        "lessThan": "1.6.1",
        "status": "affected",
        "version": "unspecified",
        "versionType": "custom"
      }
    ]
  },
  {
    "platforms": [
      "Linux/Unix"
    ],
    "product": "AWS IoT Device SDK v2 for C++",
    "vendor": "Amazon Web Services",
    "versions": [
      {
        "lessThan": "1.12.7",
        "status": "affected",
        "version": "unspecified",
        "versionType": "custom"
      }
    ]
  },
  {
    "platforms": [
      "Linux/Unix"
    ],
    "product": "AWS IoT Device SDK v2 for Node.js",
    "vendor": "Amazon Web Services",
    "versions": [
      {
        "lessThan": "1.5.3",
        "status": "affected",
        "version": "unspecified",
        "versionType": "custom"
      }
    ]
  },
  {
    "platforms": [
      "Linux/Unix"
    ],
    "product": "AWS-C-IO",
    "vendor": "Amazon Web Services",
    "versions": [
      {
        "status": "affected",
        "version": "0.10.4"
      }
    ]
  }
]