Angular Security Rules for TSLint

These simple linting rules flag points of interest where a security problem may be present in TypeScript Angular code. These rules are to be used with TSLint.

Getting Started

TSLint must be installed locally in the target project. And the project must have tsconfig.json file in the root folder. Install tslint-angular-security from npm.

cd targetproject
npm init -y
npm i tslint typescript
npm i tslint-angular-security
./node_modules/tslint/bin/tslint --init

Configuration

Configure the target project tslint.json file to include the needed rules from the tslint-angular-security package.

{
  "rulesDirectory": [
    "node_modules/tslint-angular-security"
  ],

  "rules": {
    "flag-local-storage-angular-plugin": true,
    "no-bypass-security": true,
    "no-element-reference": true
  }
}

See example configuration in tslint_custom_rules.json.

Running

In the root of the target project run:

./node_modules/.bin/tslint --project tsconfig.json --config tslint.json

Warning: This repository is a work-in-progress. Things may break while we transition this project to open source. This is not an officially supported Synopsys product.

Rules

Rule Name	Description	Vulnerability	CWE
no-bypass-security	Flags all calls of Angular Sanitizer functions: bypassSecurityTrustHtml, bypassSecurityTrustStyle, bypassSecurityTrustScript, bypassSecurityTrustUrl, bypassSecurityTrustResourceUrl. Angular does not apply any sanitization on the passed through these functions.	Validate that the input to these functions is tainted and that the result it written into a template.	CWE-79
no-element-reference	Flags all calls to nativeElement.innerHTML, nativeElement.outerHTML, and nativeElement.querySelector. The nativeElement property of the ElementRef class allows direct access to the DOM element.	Validate that tainted data is assigned in these calls or other element manipulations, which can lead to DOM XSS.	CWE-79
flag-local-storage-angular-plugin	Flags all calls writing data to localStorage or webStorage for plugins @ngx-pwa/local-storage and angular-webstorage-service.	Validate that the data is actually written to localStorage and not sessionStorage, and that the data is sensitive.	CWE-922

Developing

Feel free to update/add new rules in your local version. After you add/update the .ts, compile them using the TypeScript compiler from the root folder:

tsc

The compiled JavaScript files will be in the root directory. Copy them to node_modules\tslint-angular-security in the target project and use them.

Authors

• Ksenia Peguero, Senior Research Lead @Synopsys

License

This software is released by Synopsys under the MIT license.

Acknowledgments

• Thanks to Lewis Ardern for inspiration with his security rules for AngularJS https://github.com/LewisArdern/eslint-config-angular-security