Using clear-text protocols exposes data in transit to eavesdropping and man-in-the-middle attacks.

Why is this an issue?

An attacker who can observe network traffic — for example through a compromised network device, a position on the same network segment, or a cloud environment breach — can read, modify, or inject data sent over ftp, telnet, http, or unencrypted SMTP without detection. This is true even on internal or isolated networks, where insider threats or lateral movement after an initial compromise can expose unencrypted traffic. This rule raises an issue when a clear-text protocol scheme is used or when encryption is explicitly disabled for a network connection.

What is the potential impact?

Sensitive data exposure

An attacker who can intercept network traffic can read all data transmitted over clear-text connections, including credentials, session tokens, API keys, or personal data.

Data tampering

Because clear-text protocols provide no integrity protection, an attacker in a man-in-the-middle position can silently modify data in transit — redirecting users to malicious endpoints, injecting malicious content into responses, or altering commands sent to remote services.

How to fix it in Node.js

Code examples

The following code uses a clear-text protocol or disables encryption for a network connection, leaving transmitted data exposed to interception.

Noncompliant code example

url = "http://example.com"; // Noncompliant
url = "ftp://anonymous@example.com"; // Noncompliant
url = "telnet://anonymous@example.com"; // Noncompliant

For nodemailer:

const nodemailer = require("nodemailer");
let transporter = nodemailer.createTransport({
  secure: false, // Noncompliant
  requireTLS: false // Noncompliant
});

Compliant solution

url = "https://example.com";
url = "sftp://anonymous@example.com";
url = "ssh://anonymous@example.com";

For nodemailer one of the following options must be set:

const nodemailer = require("nodemailer");
let transporter = nodemailer.createTransport({
  secure: true,
  requireTLS: true
});

How to fix it in AWS Elastic Load Balancing

Code examples

The following code uses a clear-text protocol or disables encryption for a network connection, leaving transmitted data exposed to interception.

Noncompliant code example

For aws-cdk-lib.aws-elasticloadbalancingv2.ApplicationLoadBalancer:

import { ApplicationLoadBalancer } from 'aws-cdk-lib/aws-elasticloadbalancingv2';

const alb = new ApplicationLoadBalancer(this, 'ALB', {
  vpc: vpc,
  internetFacing: true
});

alb.addListener('listener-http-default', {
  port: 8080,
  open: true
}); // Noncompliant

alb.addListener('listener-http-explicit', {
  protocol: ApplicationProtocol.HTTP, // Noncompliant
  port: 8080,
  open: true
});

Compliant solution

For aws-cdk-lib.aws-elasticloadbalancingv2.ApplicationLoadBalancer:

import { ApplicationLoadBalancer } from 'aws-cdk-lib/aws-elasticloadbalancingv2';

const alb = new ApplicationLoadBalancer(this, 'ALB', {
  vpc: vpc,
  internetFacing: true
});

alb.addListener('listener-https-explicit', {
  protocol: ApplicationProtocol.HTTPS,
  port: 8080,
  open: true,
  certificates: [certificate]
});

alb.addListener('listener-https-implicit', {
  port: 8080,
  open: true,
  certificates: [certificate]
});

How to fix it in Amazon ElastiCache

Code examples

The following code uses a clear-text protocol or disables encryption for a network connection, leaving transmitted data exposed to interception.

Noncompliant code example

For aws-cdk-lib.aws-elasticache.CfnReplicationGroup:

import { CfnReplicationGroup } from 'aws-cdk-lib/aws-elasticache';

new CfnReplicationGroup(this, 'example-implicit', {
  replicationGroupDescription: 'exampleDescription'
}); // Noncompliant

new CfnReplicationGroup(this, 'example-explicit', {
  replicationGroupDescription: 'exampleDescription',
  transitEncryptionEnabled: false // Noncompliant
});

Compliant solution

import { CfnReplicationGroup } from 'aws-cdk-lib/aws-elasticache';

new CfnReplicationGroup(this, 'example-explicit', {
  replicationGroupDescription: 'example',
  transitEncryptionEnabled: true
});

How to fix it in AWS Kinesis

Code examples

The following code uses a clear-text protocol or disables encryption for a network connection, leaving transmitted data exposed to interception.

Noncompliant code example

For aws-cdk-lib.aws-kinesis.CfnStream:

import { CfnStream } from 'aws-cdk-lib/aws-kinesis';

new CfnStream(this, 'example-cfnstream-implicit', undefined); // Noncompliant

new CfnStream(this, 'example-cfnstream-explicit', {
  streamEncryption: undefined // Noncompliant
});

For aws-cdk-lib.aws-kinesis.Stream:

import { Stream } from 'aws-cdk-lib/aws-kinesis';

new Stream(this, 'example-stream', {
  encryption: StreamEncryption.UNENCRYPTED // Noncompliant
});

Compliant solution

import { CfnStream } from 'aws-cdk-lib/aws-kinesis';

new CfnStream(this, 'example-cfnstream-explicit', {
  streamEncryption: {
    encryptionType: encryptionType,
    keyId: encryptionKey.keyId,
  }
});

import { Stream } from 'aws-cdk-lib/aws-kinesis';

new Stream(this, 'example-stream');

new Stream(this, 'example-stream-selfmanaged', {
  encryption: StreamEncryption.KMS,
  encryptionKey: encryptionKey,
});

new Stream(this, 'example-stream-managed', {
  encryption: StreamEncryption.MANAGED
});

Exceptions

No issue is reported for the following cases:

Resources

Documentation

Articles & blog posts

Standards