Security is as essential as innovation for thriving custom software, regardless of a powerful framework. Thus, despite being powerful, NestJS software requires vigilance against vulnerabilities. Reliable software development services involve strong security measures to ensure a software’s performance.
This blog discusses a strategic vulnerability management approach of a custom software development company for the NestJS software. So, keep reading!

Security best practices for the NestJS software

Check out the security best practices a custom software development company leverages to mitigate web security vulnerabilities:

Input validation and sanitization:

Mitigate vulnerabilities like SQL injection and XSS attacks by validating and sanitizing all user input.
Implement libraries like class-validator to define validation rules for incoming data (e.g., email format, username length).
Sanitize user input by removing or escaping potentially harmful characters before processing it.
Here’s an example:

// user.dto.ts
import { IsString, IsEmail, Length } from 'class-validator';

export class CreateUserDto {
  @IsString()
  @Length(5, 20)
  username: string;

  @IsString()
  @IsEmail()
  email: string;
}

Authentication and authorization:

Developers of a custom software development company can enforce robust authentication to verify user identities before granting access. Common approaches include JWT (JSON Web Token) or session-based authentication.
They can also implement authorization (e.g., role-based access control) to limit access to delicate resources based on user roles. Utilize decorators like @Roles() and @UseGuards() to enforce authorization rules at the controller or route level.
Find an example below:

// auth.controller.ts
import { Controller, Post, UseGuards } from '@nestjs/common';
import { AuthService } from './auth.service';
import { Roles } from './roles.decorator';
import { RolesGuard } from './roles.guard';

@Controller('auth')
export class AuthController {
  constructor(private readonly authService: AuthService) {}

  @Post('login')
  async login(userLoginDto: UserLoginDto) {
    // ... authentication logic
  }

  @Get('protected')
  @UseGuards(AuthGuard('jwt'), RolesGuard)
  @Roles('admin')
  getProtectedData() {
    // ... access granted to authorized users only
  }
}

Vulnerability prevention:

Maintaining updated NestJS and dependency versions is essential to address known vulnerabilities. Utilize tools like npm outdated to identify outdated packages and npm update to apply security patches. Analyzing your code for vulnerabilities can identify and mitigate risks associated with outdated dependencies.
Developers of a custom software development company can conduct regular security audits to uncover potential weaknesses. This includes code review for vulnerabilities like SQL injection and XSS, infrastructure assessment for server and network security, penetration testing to simulate attacks, and security practice reviews to evaluate access control, data encryption, logging, and monitoring practices.

Logging and monitoring:

Implementing comprehensive logging helps record software activity and detect suspicious behavior. Utilize libraries like winston or the built-in @nestjs/common logging capabilities.
Developers can integrate monitoring tools like Prometheus and Grafana to learn more about the software performance and security metrics. They also must analyze logs and monitor data to identify anomalies that might indicate security incidents.
Below is an example:

// app.module.ts
import { Module } from '@nestjs/common';
import { LoggerModule } from './logger.module';

@Module({
  imports: [
    // ... other imports
    LoggerModule,
  ],
})
export class AppModule {}

How a custom software development company implements security practices

Here are the security measures a top software development company utilizes:

Authentication (JWT):

Implementing JSON Web Tokens (JWT) for user authentication is a crucial step. JWTs are self-contained tokens containing user information and a signature.
The NestJS @nestjs/jwt module simplifies JWT integration. Developers should define a secret key that is stored securely using environment variables.
They must generate a JWT containing user data and sign it with the secret key after a successful user login. Then, they must send the JWT back to the client for inclusion in subsequent requests.
Here’s an example:

// auth.service.ts
import { Injectable } from '@nestjs/common';
import { JwtService } from '@nestjs/jwt';
import { UserService } from '../user/user.service';

@Injectable()
export class AuthService {
  constructor(
    private readonly userService: UserService,
    private readonly jwtService: JwtService,
  ) {}

  async login(userLoginDto: UserLoginDto) {
    const user = await this.userService.findByUsername(userLoginDto.username);
    // ... validate user credentials
    const payload = { username: user.username, sub: user.userId };
    return { access_token: this.jwtService.sign(payload) };
  }
}

// .env
JWT_SECRET=your_very_secret_key

Authorization (roles):

Developers can define user roles to categorize access privileges.
They must utilize decorators like @Roles('admin') to mark controllers or routes requiring specific roles.
They must also implement a RolesGuard that checks incoming JWTs for the required role and grants access only if authorized.
Below is an example:

// roles.decorator.ts
import { SetMetadata } from '@nestjs/common';

export const Roles = (...roles: string[]) =>
  SetMetadata('roles', roles);

// roles.guard.ts
import { Injectable, CanActivate, ExecutionContext } from '@nestjs/common';
import { Reflector } from '@nestjs/core';

@Injectable()
export class RolesGuard implements CanActivate {
  constructor(private readonly reflector: Reflector) {}

  canActivate(context: ExecutionContext): boolean {
    const requiredRoles = this.reflector.get<string[]>('roles', context.getHandler());
    if (!requiredRoles) {
      return true;
    }
    const request = context.switchToHttp().getRequest();
    const user = request.user;
    return user && user.roles && user.roles.some(role => requiredRoles.includes(role));
  }
}

// app.controller.ts
import { Controller, Get, UseGuards } from '@nestjs/common';
import { AuthGuard } from '@nestjs/passport';
import { RolesGuard } from './roles.guard';
import { Roles } from './roles.decorator';

@Controller('app')
export class AppController {
  @Get()
  @UseGuards(AuthGuard('jwt'))
 getPublicData() {
    // ... accessible to all authenticated users
  }

  @Get('admin')
  @UseGuards(AuthGuard('jwt'), RolesGuard)
  @Roles('admin')
  getAdminData() {
    // ... accessible only to users with the 'admin' role
  }
}

Route protection:

Developers of a software development firm must secure routes with guards to restrict access based on user roles or authentication status.
The @nestjs/passport module facilitates integration with various authentication strategies.
They must utilize AuthGuard('jwt') to protect routes requiring a valid JWT for access.

// Refer to Authorization (Roles) section for code examples.

Authentication service:

Develop a dedicated service for user authentication logic.
This service handles tasks like user credential verification, token generation, and potentially user registration.

// Refer to Authentication (JWT) section for code examples.

Data protection:

Developers must encrypt sensitive data like user passwords and access tokens to safeguard confidentiality.
They should utilize a robust hashing algorithm like bcrypt to store passwords securely.
Also, they must consider encrypting access tokens at rest using a separate encryption key.
Here’s an example:

// user.service.ts
import { Injectable } from '@nestjs/common';
import { User } from './user.entity';
import * as bcrypt from 'bcrypt';

@Injectable()
export class UserService {
  async hashPassword(password: string): Promise<string> {
    const saltRounds = 10;
    return await bcrypt.hash(password, saltRounds);
  }

  async registerUser(createUserDto: CreateUserDto): Promise<User> {
    const hashedPassword = await this.hashPassword(createUserDto.password);
    const newUser = new User();
    newUser.username = createUserDto.username;
    newUser.password = hashedPassword;
    // ... persist user to database
    return newUser;
  }
}

Configuration and secret security:

Developers store sensitive configuration data, like database credentials and JWT secret keys, securely using environment variables. A custom software development company ensures these practices are followed for enhanced security.
The @nestjs/config module simplifies environment variable access within the software.
They should never commit environment files containing secrets to version control systems.
Below is a code sample:

// .env
DB_HOST=your_database_host
DB_USER=your_database_user
DB_PASSWORD=your_very_secret_database_password
JWT_SECRET=your_very_secret_key

// app.module.ts
import { Module } from '@nestjs/common';
import { ConfigModule } from '@nestjs/config';

@Module({
  imports: [
    ConfigModule.forRoot({ envFilePath: '.env' }),
  ],
  // ... other imports
})
export class AppModule {}

// app.service.ts
import { Injectable } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';

@Injectable()
export class AppService {
  constructor(private readonly configService: ConfigService) {}

  getHello(): string {
    const dbHost = this.configService.get('DB_HOST');
    // ... use configuration data securely
    return 'Hello World!';
  }
}

Rate limiting and CSRF protection:

Developers must implement rate limiting to mitigate brute-force attacks and abuse. Third-party middleware libraries like express-rate-limit can be integrated with NestJS.
They can enforce CSRF (Cross-Site Request Forgery) protection to prevent unauthorized actions through forged requests. Libraries like csurf can be used to generate and validate CSRF tokens.

Additional security measures for NestJS

Here are the additional security measures that a custom software development company can leverage:

Logging and monitoring:

Integrating logging libraries like winston or utilizing the built-in @nestjs/common logging capabilities.
Configuring logging levels (debug, info, warn, error) to capture relevant events.
Sending logs to centralized log management solutions (e.g., ELK Stack) for analysis and visualization.
Leveraging monitoring tools like Prometheus and Grafana to track software performance metrics and security-related indicators. Analyze logs and monitor data to detect anomalies that might indicate security incidents.
Below is a code snippet:

// .env
DB_HOST=your_database_host
DB_USER=your_database_user
DB_PASSWORD=your_very_secret_database_password
JWT_SECRET=your_very_secret_key

// app.module.ts
import { Module } from '@nestjs/common';
import { ConfigModule } from '@nestjs/config';

@Module({
  imports: [
    ConfigModule.forRoot({ envFilePath: '.env' }),
  ],
  // ... other imports
})
export class AppModule {}

// app.service.ts
import { Injectable } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';

@Injectable()
export class AppService {
  constructor(private readonly configService: ConfigService) {}

  getHello(): string {
    const dbHost = this.configService.get('DB_HOST');
    // ... use configuration data securely
    return 'Hello World!';
  }
}

Input validation and sanitization:

Implementing libraries like class-validator to define validation rules for incoming data (e.g., email format, username length, allowed characters).
Sanitizing user input by removing or escaping potentially harmful characters before processing it. This prevents vulnerabilities like SQL injection or XSS attacks.
Here’s an example:

// user.dto.ts
import { IsString, IsEmail, Length } from 'class-validator';

export class CreateUserDto {
  @IsString()
  @Length(5, 20)
  username: string;

  @IsString()
  @IsEmail()
  email: string;
}

// user.controller.ts
import { Controller, Post, Body } from '@nestjs/common';
import { CreateUserDto } from './user.dto';
import { UserService } from './user.service';

@Controller('user')
export class UserController {
  constructor(private readonly userService: UserService) {}

  @Post()
  async create(@Body() createUserDto: CreateUserDto) {
    // Validate user data before processing
    await this.userService.createUser(createUserDto);
  }
}

Continuous security testing:

Integrating tools like OWASP ZAP for automated security testing in a custom software development company throughout the development lifecycle.
ZAP scans softwares for vulnerabilities like SQL injection, XSS, and insecure configurations.
Scheduling regular scans to proactively identify and address security weaknesses before deployment.

Error handling and reporting:

Implementing robust error handling to gracefully handle unexpected errors and prevent software crashes.
Logging errors with relevant details (timestamps, error messages, stack traces) for debugging and security analysis.
Considering the implementation of custom error classes to categorize and handle different error types.
Configuring error reporting tools to send critical errors to centralized platforms for notification and investigation.
Below is an example:

// app.filter.ts
import { Catch, ArgumentsHost, HttpException, HttpStatus } from '@nestjs/common';

@Catch()
export class AllExceptionsFilter implements ExceptionFilter {
  catch(exception: HttpException | Error, host: ArgumentsHost) {
    const ctx = host.switchToHttp();
    const response = ctx.getResponse();
    // Log error details
    if (exception instanceof HttpException) {
      response.status(exception.getStatus()).json({
        statusCode: exception.getStatus(),
        message: exception.message,
      });
    } else {
      console.error(exception);
      response.status(HttpStatus.INTERNAL_SERVER_ERROR).json({
        statusCode: HttpStatus.INTERNAL_SERVER_ERROR,
        message: 'Internal Server Error',
      });
    }
  }
}

// app.module.ts
import { Module } from '@nestjs/common';
import { AllExceptionsFilter } from './all-exceptions.filter';

@Module({
  // ... other imports
  providers: [
    {
      provide: APP_FILTER,
      useClass: AllExceptionsFilter,
    },
  ],
})
export class AppModule {}

Secure session management:

Utilizing sessions and configuring secure session storage mechanisms by developers of a custom software development company.
Avoiding sensitive data stored directly in sessions. Utilize in-memory stores or signed cookies with short expiry times.
Implementing session rolling to periodically regenerate session IDs to mitigate session hijacking attacks.
Considering database-backed session stores usage with strong encryption at rest.

Security headers and CSP (Content Security Policy):

Implementing security headers using middleware like helmet to mitigate common web vulnerabilities.
Enabling headers like X-XSS-Protection, Strict-Transport-Security (HSTS), and Content-Security-Policy (CSP).
Configuring CSP to restrict the sources from which scripts, styles, images, and other resources can be loaded. This helps prevent injection attacks and unauthorized content execution.
Below is an example:

// main.ts
import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import helmet from 'helmet';

async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  app.use(helmet());
  // Configure additional security headers as needed
  await app.listen(3000);
}
bootstrap();

Secure file uploads:

Validating and securing file uploads prevents malicious file submissions.
Defining allowed file types and size limits to restrict potential threats.
Utilizing libraries like multer for disk storage or cloud storage integration.
Implementing file scanning for malware or other threats before processing or storing uploaded files.
Find an example below:

// user.controller.ts (modified)
import { MulterModule } from '@nestjs/multer';
import * as multer from 'multer';

const storage = multer.diskStorage({
  destination: './uploads',
});

const upload = multer({ storage });

@Controller('user')
export class UserController {
  constructor(private readonly userService: UserService) {}

  @Post()
  @UseInterceptors(FileInterceptor('profile_picture', upload))
  async create(
    @Body() createUserDto: CreateUserDto,
    @UploadedFile() profilePicture?: Express.Multer.File,
  ) {
    // Validate user data and uploaded file
    await this.userService.createUser(createUserDto, profilePicture);
  }
}

Conclusion

This is all about the practices of vulnerability management for NestJS software. These practices fortify the development process, mitigate risks, and improve software reliability. A custom software development company can ensure secure NestJS software by adhering to these standards.

Custom Software Development: https://www.unifiedinfotech.net/services/custom-software-development/