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Beginners guide to XSSer

Hello, aspiring ethical hackers. In one of our previous blogposts, you learnt what XSS vulnerability is, what are the different types of XSS vulnerabilities and its impact on web security. Wouldn’t it be good if there was a tool that can automatically detect and exploit XSS vulnerabilities? In this blogpost, you will be learning about one such tool named XSSer which is an automatic framework to detect, exploit and report XSS vulnerabilities in web applications.

XSSer is a python script and can be installed on all Linux systems with python installed. It is installed by default in Kali Linux and we are going to use the same for this tutorial. See how to install kali Linux in virtual Box. We will be using Mutillidae in Metasploitable 2 as target to test with XSSer as it is easily available to download and this tutorial is easily reproducible. See how to install Metasploitable 2 in VirtualBox.

Mutillidae is a vulnerable web app that intentionally consists of all OWASP 10 vulnerabilities for practicing web application hacking. Also see how to create a virtual hacking lab in virtual Box. In the page shown below belonging to Mutillidae, the blog entry field consists of a XSS vulnerability. These vulnerable pages can be detected using web vulnerability scanners like OWASP ZAP aka Zaproxy, Nikto and Burpsuite etc.

XSSer can also be used to scan for XSS vulnerabilities using the “–all” option” as shown below.

However, here XSSer failed to find any XSS vulnerability. Let’s see how to find any XSS vulnerability in this specific section. For this, I start OWASP ZAP as intercepting proxy to capture web requests. Then, I change the setting in the browser to access the web through this proxy and visit the vulnerable page again on this browser.

I type “This is a new blogpost” in the blogpost entry and save the blogpost. Now, when we view the captured web request in OWASP ZAP as shown below, we can see the request being sent to the target.

Now, we copy the highlighted data above and use it in our XSSer tool. The only difference is to find out the XSS vulnerability, we add text “XSS” in the place of any vector that us vulnerable to XSS.

Note the method the query is using to pass this data. There are two methods by which data is sent and received: GET and POST. XSSer has an option to use both the methods: (-g) for GET method and (-p) for POST method. OWASP ZAP has shown us that this data is being passed using the POST method. So, we will be using the same with XSSer.

Now, you can see that vector “blog_entry” is vulnerable to cross site scripting using URL method. Here, we tried one vector. XSSer provides an option to inject a list of vectors provided by XSSer. To test all these vectors, we can use the “—auto” option. XSSer in total has 1291 injection vectors.

As you can see, XSSer found 1287 of 1291 injection vectors in the web app. XSSer also has the option of using payloads. Here the payload can be anything even the most popular <script> alert (“HC”)</script). Here is how we specify the payload in XSSer.

Here I have given the same above-mentioned script as payload.

Specify your own payload

Using the “-Fp” option, you can even specify your own payload for final injection.

Execute payload remotely

The “-Fr” option is used to execute the payload remotely.

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Complete guide to web application hacking

Hello, aspiring ethical hackers. In this blogpost, you will learn about web application hacking. Based on research of Verizon, web applications were the most exploited vector in hacking incidents and data breachers that happened last year (2023).

According to the CyCognito State Of Web application Security Testing 2024 report, each organization exposes 100s of web applications to the web out of which 70% are untested for any security vulnerabilities. These web applications provide a large attack surface which can easily be exploited by hackers. To understand threats to web applications you need to thoroughly understand what a web application is, what is web application hacking, types of attacks that affect web applications etc.

What is a web application?

A web application is any program or application that is rendered through web browsers. Any app that you use through the browser without downloading it to your Desktop or Laptop is a web app. Example of web applications are Gmail, Netflix, Yahoo, Canva etc.

A web application is hosted on a web server and application server. A web server consists of both hardware and software components. Examples of popular web server software are Apache, NGINX, Microsoft IIS, Lighthttpd, node.js, Apache Tomcat and LiteSpeed etc. To store data, web servers use a database. Most popular databases in use are MySQL, Oracle, Microsoft SQL Server, PostgreSQL, MongoDB, Redis, MariaDB, Splunk, SQLite etc.

Similar to a website, a web application is written in HTML/CSS, JavaScript and it uses PHP/ASP for server side programming and Database for storing data etc. Apart from a web server there is also presence of an application server to serve web apps.

What is web application hacking?

Hacking of these web applications to compromise the entire web server or the entire network is known as web application hacking.

Types of web application attacks

There are many attacks that can be used to compromise web applications..

1. Remote File Inclusion (RFI) attack

2. Local File Inclusion attack

3. SQL injection attack

4. Cross-site scripting (XSS) attack

5. OS Command Injection attack

6. Cross site Request Forgery (CSRF) attack

7. Password cracking attack

8. Session Hijacking attack

9. Server side request forgery (SSRF) attack

Impact of a web application hacking

Compromise of a web application can have many affects. Most important of them are,

1. Data breach and Data theft:

Compromise of a web application can result in a data breach and data theft.

2. Leak of sensitive information:

Sometimes, a web application compromise can leak sensitive information about a company or organization.

3. Web app defacement:

Every web application has an index page that is the page that loads when you visit a website. When hackers change the index page and replace it with another page, it is known as website defacement.

4. Secondary attacks:

Once a web application is compromised, it can be used by hackers for other malicious purposes like hosting malware, to perform a DDoS attack or using it as a proxy to perform attacks on other websites.

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Beginners guide to ethical hacking

Hello aspiring ethical hackers. In this blogpost, you will learn in detail about ethical hacking. As the cybersecurity threat landscape is continuously evolving, the role of ethical hacking role in protecting the organizations is also increasing. But what exactly is ethical hacking?

What is Ethical Hacking?

Ethical hacking is the process of hacking into a system, network or application but with the permission or authorization of the owner of the resource. In simple terms ethical hacking is gaining access to someone’s system, network or application with their prior permission. Ethical hacking is performed to detect and find any threats or vulnerabilities malicious hackers in real-world may exploit and then patch them to improve the security of the organization.

Terminology of ethical hacking

To understand hacking, you need to have a basic understanding of some of the terms related to hacking. They are,

1. Asset:

In an organization, anything of value is considered as an asset. For example, employee records of the organization, employee credentials, records of its customers, the servers, computers etc are considered of value to the organization.

2. Threat:

Any action or event that can disrupt the organization’s activities can be termed as threat. For example, these actions can be deleting the user accounts of employees of the organization, making their services unavailable to their customers etc.

3. Vulnerability:

A vulnerability is a weakness in the system application or network of the organization.

4. Exploit:

The programing code written to take advantage of this vulnerability is known as exploit. (A zero-day vulnerability is a vulnerability which doesn’t have any patch yet).

5. Patch:

Code written to mitigate the vulnerability in the system, application or network is known as a patch. (You should have heard of Exploit Database. As the name of the website implies, it hosts all the exploits or POC’s. A proof of Concept is the exploit code written to demonstrate the vulnerability.

6. Payload:

In hacking, exploit takes advantage of the vulnerabilities. After exploiting the vulnerability, hackers usually run specific code. This code is known as payload. For example, ms_08_067 is a vulnerability which is exploited by the exploit module of same name, while meterpreter is the payload. Learn more about the payloads here.

7. Impact:

The damage done to the asset due to exploitation of vulnerability is known as impact.

Types of hackers

A person performing ethical hacking is known as an ethical hacker. You have learnt that a person performing hacking is known as a hacker. Based on the type of hacking they perform; hackers can be classified into different types. They are,

1. Black Hat Hacker:

A Black Hat Hacker is a hacker who performs all illegal hacking attacks. These are the villains in the domain of hacking.

2. White Hat Hacker:

If there are bad guys of hacking, there are bound to be good guys of hacking. White Hat hackers are the good guys of hacking. They protect the organizations from the Black Hat Hackers.

3. Grey Hat Hacker:

Like the Grey zone, these hackers are in the group of ambiguous zone, who cannot be necessarily called Black Hat or White Hat hackers. For example, a person working as a White Hat Hacker in day and taking Black Hat assignments at night.

4. Green Hat Hacker:

Green Hat Hackers are those hackers who have no knowledge but are “experts” at using readymade tools and exploits made by Elite Hackers.

5. Red Hat Hacker:

Red Hat Hackers are White Hat Hackers that try to take down or prevents Black Hat Hackers. They sometimes use aggressive tactics to achieve their goal.

6. Blue Hat Hacker:

Blue Hat Hackers (also known as Blue Teams) are hired to test the organization for any vulnerabilities or weaknesses. They are similar to White Hat Hackers but are extreme.

7. Hacktivist:

A hacktivist is a type of hacker who hacks to promote a political or social or environmental cause.

8. Elite Hackers:

At the opposite ends of Green Hat Hacker or script kiddie, we have the Elite Hackers who have deep knowledge of hacking. He/she likes to write his/her own exploits, find zero-days etc.

9. Advanced Persistent Threats (APTs):

APT’s are state-sponsored hackers (more rightly hacker groups) that are specifically used to target enemy nations, perform cyber espionage, collect information etc.

What are the 5 phases of ethical hacking?

Ethical hacking consists of 5 phases. They are,

1. Foot printing:

Also known as information gathering or reconnaissance, in this phase ethical hackers try to collect as much information as possible about the target organization or individual that may be helpful to them in the next phases of ethical hacking. Learn more about Footprinting.

2. Scanning & enumeration:

In this phase, the target organization’s network is probed to find any path of entry that can provide a way for ethical hackers into the network. It includes scanning for live systems in the network range, scanning for open ports on the LIVE systems and services running on them and scanning for any vulnerabilities in those services.

Then these services are enumerated to find any user accounts or other Information about the target networks. Learn more about scanning & enumeration.

3. Gaining access:

In this phase ethical hacking, ethical hackers exploit one of the vulnerability or weakness found in the second phase and gain a shell on the target system or network. Learn more about gaining access.

4. Maintaining access:

In this phase, ethical hackers after gaining initial access on the target system or network, try to maintain this access for future and continuous use. Learn more about various techniques used for maintaining access.

5. Covering tracks:

In this phase, ethical hackers try to hide or erase all their operations performed on the target system or network until now. This is to remove any evidence of their malicious activity. In Black Hat Hacking, they do this to prevent tracing of the hack back to them. This phase is also known as clearing tracks. Learn more about covering tracks.

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Beginners guide to OSINT

Hello, aspiring ethical hackers. In this blogpost, you will learn what is OSINT. In our previous articles, you learnt about the 5 phases of ethical hacking, you learnt the importance of footprinting of ethical hacking. OSINT is a part of footprinting.

What is OSINT?

OSINT stands for Open Source Intelligence. OSINT is a method of gathering information from all open sources. Open sources are those which are publicly available and are free to access. OSINT is used by hackers, pen testers and Red-Team professionals to collect information about an organization or people that can be used in gaining access or performing social engineering.

These sources of OSINT can be social media sites like Instagram, LinkedIN etc, newspapers, news sites, blogs or shopping sites, search engines, metadata, Google docs, forums, etc.

For example, LinkedIN company pages reveal information about all the employees of the organization. These employees have their job description listed in their profile. Let’s say there is an employee whose role is “Solaris admin”. From this, you can say that the particular company is using Solaris as they have an employee for that job (unless that particular company is using ADVANCED TO THE POWER OF 100 trade craft to hide the original software they are using.

Now a hacker group creates a fake profile of a company on LinkedIN, connects with this user, sends a proposal for a job with increased salary for the same role. They ask his/her email for further communication.

Top OSINT tools

Here are some of the top OSINT Tools used by Cyber security professionals.

  1. Maltego: Maltego is link analysis software that is used to gather real-world relationship between roles, groups, domains, email addresses, webpages, social media accounts etc. Learn more about this tool here.
  2. Google Dorks: Often underestimated, Google dorks also can be useful to gather more information about a person or companhy. Learn more about it here.
  3. Spiderfoot: Spiderfoot is an OSINT tool written in Python that queries over 100 public data sources to gather information about any IP address, domain name, names of person and email address.
  4. Shodan: Popularly called the hackers search engine, Shodan lets users search for various or types of servers connected to the internet using a variety of filters.
  5. Metagoofil: Metagoofil is tool used to extract metadata from publicly available documents like PDFs, DOC, XLS, PPTX, DOCX, PPTXS.

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Remote code execution(RCE) for beginners

Hello, aspiring ethical hackers. In this blogpost, you will learn about Remote Code Execution (RCE) vulnerability. RCE is considered one of the most dangerous vulnerability that can impact systems or software.

What is remote code execution (RCE)?

Remote code execution vulnerability allows an attacker to execute code or commands on a remote machine. Code execution on the local system is itself dangerous. Consider hackers having remote access to the machine and about to execute arbitrary commands on the system. As it is a hacker, you can consider that the code being executed is always malicious. This code can be anything like malware, payloads etc.

Vulnerabilities that lead to remote code execution

Any vulnerability that can lead to hackers being able to execute code on the remote machine leads to remote code execution.

  1. Local File execution
  2. Buffer overflow
  3. SQL Injection
  4. Cross site scripting (XSS)
  5. Deserialization
  6. Command Injection
  7. File upload
  8. CSRF
  9. Out of Bounds write
  10. SSRF

Impact and execution

Remote code execution can have a dangerous impact that can lead to gaining access, privilege escalation etc. For this reason, it is always considered a CRITICAL vulnerability. Some of the examples of RCE vulnerabilities are,

  1. ms08_067 vulnerability
  2. EternalBlue
  3. PrintNightmare
  4. Log4shell.
  5. Spring4shell.
  6. Shellshock.