Understanding the Toughest Layer 7 Attacks and How to Prevent Them

In the fast-paced, ever-changing world of cyber security, Layer 7 attacks have become a concerning trend that continues to affect users and entire organizations. Cybercriminals continue developing increasingly advanced attacks and tactics, so it’s important to understand Layer 7 attacks and how to develop an effective cyber security strategy  .

Layer 7, also known as the application layer, of the OSI model is the layer that users utilize to interact with computer systems. This is the application interface we use to enter data, which is why this layer is so vulnerable. When attackers exploit features of this layer, they can control systems and cause maximum damage.

Implementing proper preventative measures is crucial when protecting against cyber attacks. Partnering with a reliable managed security services   provider, such as PurpleSec, can provide the expertise, tools, and technologies needed to prevent cyber attacks and safeguard your systems and data.

In this article, we will highlight the toughest Layer 7 attacks that currently exist today, what makes each of these attacks so effective, and how you can avoid them.

The Toughest Layer 7 Attacks

Below are the toughest Layer 7 attacks and helpful tips to prevent them.

1. SQL Injection

SQL injection is one of the most common Layer 7 threats that exploit vulnerabilities in web applications attached to databases. Cybercriminals carry out this attack by injecting malicious SQL code into a web application, usually through search boxes, text input fields, or login forms.

The attacker tricks the application into executing a command the system should not allow, such as creating a new user, elevating system privileges, or taking over the entire system.

A successful SQL injection attack can be catastrophic for a company. Data breaches, financial and reputational damage, and even legal liabilities are very possible outcomes. Customers will lose trust in the company, further damaging the organization.

How to Prevent SQL Injection Attacks

Preventing an SQL injection attack starts during the design phase of the application. Designers must implement measures such as:

• Input Validation: This process checks and validates data or information entered or received by a system. It ensures the data meets certain criteria or rules before being accepted or processed further. Input validation prevents SQL injection attacks by checking and cleaning the data to ensure it contains no malicious or unexpected characters or SQL commands.
• Parameterized Queries: This method separates data from the query when interacting with a database and uses placeholders to represent the data. With parameterized queries, the data is treated separately from the query. Even if the data contains malicious characters or commands, they are treated as data rather than part of the query.
• Least Privilege Access: This method grants only the bare minimum required for users to interact with the application. Least privilege access can help prevent SQL injection attacks by only giving the user or application the necessary permissions to perform legitimate database operations and nothing more.

Prevention techniques are crucial in protecting systems against SQL injection attacks. Web applications are especially vulnerable, so you must safeguard your application to avoid falling prey to this preventable but damaging attack.

2. Cross-Site Scripting (XSS)

Cross-site scripting (XSS) attacks also use injection as their method of attack. This time, scripts are injected into web applications, causing unauthorized actions that compromise the system.

One of the most well-known attacks was the Samy Worm in 2005 on the social media platform MySpace. Samy Kamkar created a worm that used a stored XSS vulnerability to execute malicious code.

The malicious code would execute on the visitor’s browser whenever a MySpace user visited Samy’s profile, automatically causing the platform to add Samy as their friend. Within 24 hours, Samy had over 1 million friends on MySpace, and the platform had to shut down to remove the vulnerability.

How to Prevent Cross-Site Scripting Attacks

Preventing this type of attack can be accomplished by implementing the following:

• Output Encoding: This method converts data or information from one form or representation into another. When data is encoded, it is converted into a safe format that cannot be interpreted as code by a web browser.
• Content Security Policies (CSP): This method allows website administrators to specify which content sources are allowed to be loaded and executed by a web page. When a web page loads in a browser, the browser checks the CSP rules defined by the website. If a script found on the web page does not comply with the CSP rules, the browser will block the execution of that script, preventing the XSS attack from being successful.

Malicious parties will try to use legitimate areas of a web application to carry out an attack. These preventative fixes must be put in place from the beginning of the application design process.

3. Cross-Site Request Forgery (CSRF)

Cross-site request forgery (CSRF) is another method used by cybercriminals to try and gain access to web applications and user data. The attack involves tricking users into executing an operation unintentionally.

If the user clicks on one of these links, they get redirected to an infected site hosting malware. The infection will either enter their system upon visiting or performing actions on the site.

The malware will make requests to legitimate sites using the victim’s credentials cached in the browser. This can cause massive damage if services like internet banking and other financial platform credentials are compromised.

How to Prevent Cross-Site Request Forgery Attacks

To safeguard against CSF attacks, you should implement the following:

• CSRF Tokens: This method uses unique, randomized tokens that are linked to the individual user’s session. The tokens are included in every request, ensuring that the user is actually requesting an authorized session.
• SameSite Cookies: SameSite cookies restrict browsers and cross-site requests, reducing the overall risk of CSRF attacks.

Implementing these security measures greatly reduces the likelihood of CSRF attacks.

4. Distributed Denial of Service (DDoS) Attacks

Layer 7 DDoS attacks aim to take a service offline by overwhelming the application layer with floods of automated, seemingly legitimate traffic. The web server has no choice but to accept requests until it can no longer serve them. At that point, the web server either times out, crashes, or goes offline.

These attacks are different from traditional DDoS attacks that target lower levels of the OSI model because it seeks to delete application resources, not the server itself. This makes it far harder to diagnose and troubleshoot an issue when the traffic appears legitimate.

How to Prevent Distributed Denial of Service Attacks

Luckily there are ways to mitigate and prevent Layer 7 DDoS attacks:

• Rate Limiting: This limits the number of requests made to the application within a predefined time frame. Rate limiting prevents an attack from being carried out and slows down the depletion of system resources for your web application.
• IP Filtering: If suspicious IP addresses are detected, IP filtering will block addresses that exhibit the same behavior. Examples are IP addresses that make high volumes of requests and repeated failed attempts.
• Traffic Analysis: Analyzing network traffic patterns and implementing anomaly detection techniques can help identify and block suspicious traffic before it reaches the application layer. This can be done by using penetration testing tools that constantly monitor and analyze network traffic for any signs of DDoS attacks.

By using these relatively straightforward prevention strategies, you can mitigate a large percentage of Layer 7 attacks on your web-facing services.

5. Insecure Deserialization

Insecure deserialization is another method that attackers use to affect the operation of an application or website. Data flows are interrupted by attackers so that code is injected into the application before it finishes deserializing, allowing for malicious code to be executed.

If this is successful, attackers can gain remote access to the system and escalate their privileges.

The consequences of such an attack are severe, as it gives the attacker access to the application and effective control over the system. This could give them access to sensitive data and user information.

How to Prevent Insecure Deserialization Attacks

In order to prevent attacks of this kind, you will need to ensure the following is in place:

• Sanitize Sterilized Data: Implement validation and sanitization checks on the serialized data before deserializing it. This can involve checking for unexpected or malicious data, such as objects with harmful properties or unexpected data types, and rejecting or sanitizing them to prevent the execution of malicious code.
• Input Validation: Only deserialize data from trusted sources. Do not deserialize data from untrusted sources, such as user inputs, external APIs, or other unverified sources. Implement strict input validation and filtering to ensure only trusted data is passed for deserialization.
• Vulnerability Assessment: Regularly conducting vulnerability assessments of web applications can help identify and fix any vulnerabilities that could be exploited by cybercriminals to launch Layer 7 attacks. Vulnerability assessment tools can scan web applications for known vulnerabilities and provide recommendations for fixing them.

Enhance Your Cyber Security With PurpleSec

Layer 7 attacks pose a significant threat to organizations and individuals as cybercriminals continue developing advanced techniques to exploit vulnerabilities in web applications and systems.

SQL injection, cross-site scripting (XSS), cross-site request forgery (CSRF), and distributed denial of service (DDoS) attacks are some of the toughest Layer 7 attacks. They can result in severe consequences such as data breaches, financial loss, reputational damage, and legal liabilities.

As cyber attacks continue to evolve, it is imperative to partner with a reliable and experienced cyber security provider like PurpleSec to stay one step ahead of cyber threats.

PurpleSec is a top-tier cyber security company that goes beyond the bare minimum. With a team of experienced cyber security professionals well-versed in the latest threats and best practices, PurpleSec offers tailored recommendations and solutions to mitigate risks and protect against cyber threats effectively.

We provide comprehensive cyber security services, including managed security, virtual CISO, vulnerability management, penetration testing, and risk assessments.

Don’t wait until it’s too late. Take action now to secure your systems and data with PurpleSec’s cutting-edge cyber security services. Contact us today to learn more and schedule a consultation. Stay secure, stay protected with PurpleSec.

Article in Collaboration with Zach Norton (@pentestzach) of Pentest-Tools.
Author: Zach Norton