Web application security testing is a process of identifying vulnerabilities in a web application and determining their impact. It involves a series of tests that use simulated malicious attacks to evaluate the security of a web application.
The process starts with a thorough analysis of the application, followed by risk assessment and reporting. Next is a set of manual testing techniques that includes both static and dynamic security testing.
Cross-site scripting (XSS)
Cross-site scripting (XSS) is a security flaw that allows malicious code to be delivered to users’ browsers. XSS attacks can be targeted at web applications, websites or email messages. They usually involve a web application that displays user-entered data, such as a form or an API endpoint, and the data is displayed without being properly sanitized or transformed into a safe format.
XSS attacks are generally categorized into two categories: non-persistent (reflected) and persistent (stored). The non-persistent type occurs when the attacker sends a payload that doesn’t include server-side output encoding. It then echoes back to the victim’s browser, which executes it.
Persistent XSS is the most dangerous because it targets websites that accept user-generated content. This includes Internet forums, message boards, guest books, and social networking platforms. An attacker posts a seemingly innocuous comment, and it contains a script that is stored on the website’s web server.
When a visitor views the comment, their browser automatically executes the script, which gives the attacker complete access to the site. This can be used to steal session tokens, cookies and confidential information that the victim has on the site, or even rewrite HTML page content.
The most effective way to protect against XSS is to sanitize all user input before it is rendered to a web page, and to limit the allowable values of user input to a safe range. Additionally, use escaped HTML characters in user input to prevent it from being processed as scripts or commands.
Another approach to securing web applications is to use automated testing functionality that can help detect and mitigate XSS vulnerabilities early in the development process. The best practice is to incorporate the defense in depth principle, which involves implementing security measures at every phase of the web application lifecycle: software design, testing and remediation.
In addition to securing web applications, it is also important to train staff on how to avoid XSS. Security training should cover the risk of XSS and how to properly handle and sanitize input. It should also highlight the different types of XSS and how they can be exploited.
SQL injection
Many web applications store data in SQL databases, which make them vulnerable to an SQL injection attack. This exploit enables hackers to access user information and manipulate data, compromising the application’s integrity and exposing sensitive information.
The first step in preventing SQL injection attacks is to use good security practices during the development phase. This includes using prepared statements and parameterized queries to ensure that the parameters passed into the SQL statement are treated safely. Object-relational mapping frameworks are also helpful in translating the results of SQL queries into code objects more seamlessly.
Another way to prevent SQL injection attacks is by limiting the permissions that database logins have in the application. This will limit the effectiveness of exploits that attempt to use passwords in clear text.
In addition, sanitize user inputs by filtering them and ensuring that no validation error messages or successful messages for malicious code are present. This approach can protect an application against SQL injection, although it may not prevent other forms of malicious code from being entered by users.
An attacker can modify SQL queries to return additional, confidential data and then download that data from the database. This form of attack is called UNION SQL injection and can be a major risk for a website or application that handles sensitive data.
There are three types of SQL injection: in-band, inferential, and out-of-band. In-band SQL injection is the most common form of attack and relies on certain database server features being enabled.
In-band SQL injection is a form of attack that uses HTTP requests to gather and execute user input and database results. It involves sending a SQL query to the database, and then waiting a certain amount of time before generating an HTTP response.
Depending on the time it takes to generate the response, an attacker can determine whether the query is true or false. This type of attack is commonly used in combination with other attack types to sabotage the application’s functionality or compromise its security.
In-band SQL injection is a technique that allows an attacker to execute code directly on the application’s server without being intercepted by a network firewall. This form of attack is usually performed against websites that use legacy web technologies that do not have built-in SQLi protection. This is a major threat to any website that stores customer data, as an attacker could steal confidential information and monetize it.
Password cracking
Password cracking is a common security flaw that can allow an attacker to gain access to a web application or system. It can also give an attacker access to databases and servers.
Hackers can use a variety of methods to try to crack passwords, including guessing, social engineering, and automated techniques. However, most passwords are stored in an encrypted form that makes it harder for hackers to crack them.
The easiest way to prevent this is to ensure that all passwords are unique and not re-used by other users. This is especially important for privileged accounts that grant access to sensitive data or functionality.
Some of the best password security practices include using strong passwords that are at least 12 characters long, combining letters and a variety of other characters, and using numbers and special characters. In addition, it is recommended to avoid using passwords that are easy to guess, such as a name or pet’s name.
Choosing strong passwords can be difficult, especially since most users are likely to reuse their passwords across multiple sites and services. To avoid this, password management tools are available that create long and hard-to-guess passwords for users.
A common password-cracking technique involves guessing passwords using trial and error methods. These guesses are often based on information that an attacker has about the victim, such as the victim’s birth date or favorite sports team.
Another common method is a brute force attack, which is where an attacker attempts a large number of passwords in a short period of time. This is not a good strategy for most organizations, because it can cause account lock-outs and trigger event logs that will leave evidence of the attack.
Many web-based applications also store user passwords in an encrypted format, which is a good defense. However, even this can be compromised by a simple brute force attack.
Dictionary attacks are a more sophisticated version of a brute force attack that leverages a list of passwords against an account to reveal the password. These password lists are commonly created from leaked or previously cracked passwords.
Access control
Access control is a form of security that controls who can access a system or data. It’s a critical aspect of IT security and a major component of many security standards.
Access controls can be applied in various ways to different systems and devices, and they vary widely according to the needs of individual organizations. Some access control methods are based on the identity of users; other models use an array of factors to determine who can gain access to a system or resource.
Role-based access control (RBAC) is one such approach that relies on a complex structure of role assignments, authorizations and permissions to regulate employee access to computer resources. It’s a highly effective solution for organizations that need to keep their sensitive information secure, as it limits access to systems and networks based on business functions rather than on the identities of individuals.
Discretionary access control (DAC) is another option, which gives users the power to set their own security settings and share permissions without having to rely on strict oversight from a system administrator. DAC is especially useful for businesses that have multiple offices and users who need to share access to resources.
For web applications, testers should look for any gaps in the application’s access control system. This could include failing to ensure that only authenticated users have access to the application.
This may result in an attacker gaining access to sensitive information and compromising the application. An attacker could steal user login information, manipulate data or compromise the web server and infrastructure.
To identify access control vulnerabilities in an application, testers should investigate the various authentication methods and tokens used within the application. This includes passwords, biometrics, key cards and other devices and methods of accessing data.
In addition, testers should verify that all identifying information is protected from being leaked or disclosed in plain text. This is particularly important if the application stores customer data or sensitive and business-critical information on its servers.
Access control is one of the most important components of security in the digital world, and it’s a critical element of any web application security test. It can make or break a web application, so it’s essential to implement proper access controls when building your web application.
