How do you secure web applications at all architecture levels?

1 Front-end security

The front-end of a web application is the part that interacts with the user via the browser. It consists of HTML, CSS, and JavaScript code that renders the user interface and handles user input. To secure the front-end from malicious code injection, cross-site scripting (XSS), and cross-site request forgery (CSRF), it is essential to validate and sanitize user input before sending it to the back-end or displaying it. Frameworks and libraries such as React or Angular provide built-in protection against XSS and CSRF. Additionally, HTTPS should be used to encrypt communication between the browser and server, preventing man-in-the-middle attacks and authenticating the web application. Content security policy (CSP) and subresource integrity (SRI) should be implemented to restrict sources and hashes of external scripts and resources. Secure cookies and local storage should be used to store sensitive data on the browser; setting the HttpOnly, Secure, and SameSite attributes for cookies will prevent access by JavaScript or other domains. Furthermore, local storage data should be encrypted and expired to prevent unauthorized access or leakage.

2 Back-end security

The back-end of a web application is the part that runs on the server and handles the business logic and data processing. It consists of the programming language, framework, and middleware that receive requests from the front-end and send responses back. To protect against unauthorized access, data breaches, and denial-of-service (DoS) attacks, you should implement authentication and authorization mechanisms to verify users' identities and permissions. Secure protocols and standards such as OAuth, OpenID Connect, or JSON Web Tokens (JWT) should be used to exchange credentials and tokens. Multi-factor authentication (MFA) and password hashing and salting should be employed to further enhance security. Additionally, encryption of data stored or transmitted by the back-end is necessary, as well as SSL/TLS certificates for secure connections between the server and database or other services. Cloud storage or off-site backups should be used to prevent data loss or corruption. Finally, firewalls, load balancers, rate limiters, logging, auditing, and alerting tools should be employed to monitor traffic and resources consumed by the back-end as well as track any suspicious or malicious activity or errors.

3 Database security

The database of a web application is the part that stores and manages the data used by the back-end and front-end. It consists of a database management system (DBMS) like MySQL, PostgreSQL, or MongoDB, and data models and schemas that define the structure and relationships of the data. The main security challenges for the database are preventing SQL injection, data leakage, and unauthorized access. To secure the database, you should use parameterized queries or prepared statements to execute SQL commands on the database; this will help prevent SQL injection attacks. Role-based access control (RBAC) and encryption should be used to restrict and protect the data accessed by database users and clients; assign different roles and privileges based on least privilege, and encrypt data at rest as well as in transit using encryption algorithms and keys. Finally, secure configuration and patching should be employed to maintain security and performance of the database; follow best practices of DBMS vendor to configure settings, apply security updates/patches to fix vulnerabilities/bugs.

4 Network security

The network of a web application is the part that connects the different components and layers of the architecture, such as the front-end, back-end, database, and cloud. It consists of the protocols, devices, and services that enable communication and data transfer between them. To secure the network from eavesdropping, spoofing, and hijacking, it is important to use secure protocols and standards to encrypt and authenticate traffic. HTTPS, SSL/TLS, SSH, or VPN should be used to protect data in transit from interception or tampering. DNSSEC, SPF, DKIM or DMARC should be used to verify the identity and integrity of the network domains and emails. Firewall rules and policies should be used to filter incoming and outgoing traffic based on source, destination, port or protocol. Intrusion detection and prevention systems (IDS/IPS) should be used to monitor and block network traffic. Network segmentation and isolation should also be used to separate and protect network zones with subnets, virtual LANs (VLANs), or virtual private clouds (VPCs). Access control lists (ACLs) or security groups should be used to control traffic between segments.

5 Cloud security

The cloud of a web application is the part that provides computing, storage, and networking resources hosted and managed by a third-party provider, such as AWS, Azure, or Google Cloud. It consists of cloud services and platforms that enable scalability, availability, and functionality of the web application. To secure the cloud from data breaches, misconfiguration, and vendor lock-in, encryption and key management should be utilized to protect data stored or processed. Identity and access management (IAM) and policies should be employed to manage access and permissions of cloud users and resources based on the principle of least privilege. Additionally, cloud security posture management (CSPM) and compliance should be used to ensure the security and compliance of the cloud configuration and environment. Compliance frameworks such as PCI-DSS, HIPAA, or GDPR should also be adhered to for regulatory and industry requirements.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?