Every year attackers evolve their techniques and target companies to compromise sensitive information and steal user credentials. Data breaches are growing exponentially, and developers are focused solely on fixing issues through patches post-detection. Unfortunately, most web apps don’t have security built into their design, giving way to various security threats. Some common web application security risks are listed below (StackHawk, 2023).

1. SQL Injections

SQL Injections attack application databases and allow adversaries to gain unauthorized access to sensitive information saved in databases. These attacks can steal financial data, passwords, credit card details, and personal information. They are one of the most common web hacking techniques used to destroy databases and can interfere with all queries made to application databases.

How to mitigate? You can mitigate SQL injections by validating user inputs and applying output encoding techniques. Using parameterized queries or stored procedures over dynamic SQL can also help mitigate these threats. Also, permissions to important objects such as tables should be restricted to those only required for particular operations. Excessive permissions to database objects such as drop tables must not be provided for the web application’s SQL operations. It enhances the defense-in-depth mechanism for the data present in the database.

2. Cross-Site Scripting

Cross-site scripting (widely known as “XSS attack”) involves injecting malicious code into web applications and executing it. It allows the attacker to remotely control web applications and alter configurations. By manipulating the program, the attacker is able to deceive the browser into processing the malicious script as though it were coming from a reputable source. Users’ browsers download and execute the malicious script each time they view the affected website, acting as though it were an integral element of the page. The malicious script may steal cookies, access users’ private information, or take over a user’s session. In short, users may be redirected to other malicious websites, experience website defacing, or get their session IDs stolen from these attacks.

In the area of web application security, the Open Worldwide Application Security Project (OWASP) is an online community that creates freely accessible publications, approaches, documentation, tools, and technologies. The three categories of XSS attacks identified by OWASP are stored, reflected, and DOM-based. The application or API stores the unsensitized user input in a stored XSS attack. The victim can then access the web application’s stored data without having to make it safe for the browser to render it. An application or API injects malicious code into the HTML input during a reflected XSS attack. The server sends the browser the unescaped, unvalidated response that contains malicious content. The attacker can then utilize the user’s web browser to execute any HTML or JavaScript. An XSS flaw that happens in the Document Object Model (DOM) as opposed to the HTML code is known as a DOM-based attack. In a DOM attack, the data flow never leaves the browser because both the data source and the attack response are also in the DOM.

How to mitigate? Implementing a strong content security policy and output encoding techniques can prevent cross-site scripting instances. All input data must be validated by a web application, which must also verify that only allowed listed data is permitted and that all variable output is encoded before being provided to the user. Sanitizing data is another critical step. It is advised to check for and eliminate unwanted data, such as HTML tags, that are deemed unsafe. Remove any unsafe characters from the data while keeping the safe data. OWASP AntiSamy is a popular auto-sanitization library used for remediating cross-site scripting attacks.

3. Insecure Direct Object References (IDOR)

This is a type of access control attack where the threat actor sends inputs to access objects in applications directly. A common vulnerability arises, and database references may get exposed to URLs. Users can also edit these URLs to access other critical information without requiring additional privileges or authorizations.

How to mitigate? Change the error messages in web applications and customize them so you don’t accidentally reveal sensitive information. Implement proper authorization checks at every stage of the web app’s user journey and do not disclose references to objects in URLs. In some circumstances, employing more sophisticated identifiers, such as GUIDs, might make it very hard for attackers to guess correct values. Access control checks are nevertheless necessary, even with complicated identities. Attackers should still have their access attempts blocked by the program even if they manage to obtain URLs for forbidden items. If at all possible, keep identifiers hidden in POST and URL bodies. Instead, use session information to identify the person who is currently authenticated. Pass identifiers in the session when utilizing multi-step flows to prevent tampering. Make sure the user has given permission every time an access attempt is made.

4. Security Misconfigurations

Security misconfigurations happen when web servers and applications are configured so that security is not maximized. They pose a significant threat to entire application stacks and aren’t limited to web applications alone. Pre-installed virtual machines (VMs), custom code, databases, web applications, web servers, network services, and online platforms are targeted.

The most common security misconfigurations are changes in default account settings, unpatched systems, unencrypted files, and insufficient firewall protection. Attackers can target web application directories and exploit improper input and output data validation.

How to mitigate? The simplest way to fix web application security misconfigurations is to establish a hardening process and ensure it gets appropriately deployed in newly configured environments. Install the latest patches, regularly audit security controls, and do not allow any major configuration modifications for best results (Dizdar, 2022).

5. Outdated Components

Applications, Application Programming Interfaces (APIs), and web components may be outdated and not patched frequently. Errors may result due to insufficient updates, and attackers implant bugs in perimeter defenses. Software and data integrity failures related to continuous integration / continuous delivery (CI/CD) pipelines are also common and can be overlooked.

How to mitigate? Open-source or proprietary code that is old or has security flaws is referred to as having vulnerable and outdated components. For web applications, this code can take the shape of libraries or frameworks, such as Laravel (PHP), Angular (JavaScript), Django (Python), and many more. Update your web app security software and install the latest security patches. Ensure you configure web applications so that they auto-update at regular intervals and do not miss emerging bug fixes from developers.

6. Insufficient Security Logging and Monitoring

This web application security threat isn’t well represented in CVE/CVSS data. Common failures associated with insufficient security logging and monitoring practices include a lack of incident alerts and responses, poor visibility, missing data, and ineffective security policies that could cause severe data breaches. Attackers may expose or manipulate many unknown or hidden vulnerabilities to pivot to other systems, destroy, or tamper with information.

How to mitigate? Implement log monitoring, analysis, and management tools in web applications’ security workflows. Proper data visualization, alerting, and reporting practices can remediate insufficient security logging and monitoring. Doing regular network and web application audits is also another good practice. The sensitive logs should be stored encrypted, as those can leak sensitive information about the application if hacked.

7. Denial of Service (DoS) and Distributed Denial of Service (DDoS) Attacks

A DoS attack floods the web application with numerous requests and attempts to overuse resources, making them unavailable to others on networks. DDoS attacks target multiple web applications and attack organizations on a much larger scale. The primary purpose of DDoS and DoS attacks is to make web applications go offline and render them useless through unavailability. Protocol DDoS attacks target Layer 3 (network layer) and Layer 4 (transport layer) web apps, while application attacks target Layer 7 (application layer), where end users are the most vulnerable. Some DoS attacks, like HTTP requests on web app login pages, are small, making them harder to catch.

How to mitigate? Activate a web application firewall (WAF) and enable rate limiting on web APIs so that applications can’t process beyond a certain number of user requests. When limits are exceeded, web apps will temporarily block access to resources for users and return 429 HTTP error codes instead (Shekhawat, 2023).

8. Missing Function Level Access Control

It alludes to the authorization logic’s bugs. The attacker, who might already be using the application, can escalate privileges and gain access to restricted functionality by exploiting it. For instance, this attack frequently focuses on restricted administrator-level functions. When an attacker attempts to gain access to specific functions and features in web apps that are typically unavailable to regular users, it is referred to as missing function-level access control. A rare security defect gives them access to sensitive database information.

How to mitigate? Implement the least privilege level of access and adequate authorization measures for all relevant stages of web app usage. Deny access to features and functions by default unless pre-approved admin users attempt to access them (Sengupta, 2022).