Category: Privilege Escalation

Hello, aspiring ethical hackers. In our previous blogpost, you learnt about various linux privilege escalation techniques. In this article, you will learn about Linux exploit suggester, a script that helps us in elevating privileges on a Linux system.

Linux exploit suggester assists in detecting security deficiencies of a Linux kernel or Linux machine and suggests exploits for the vulnerabilities detected. It does this by assessing exposure of kernel to publicly known exploits. Obviously, this script should be run on target system after gaining access. Let’s see how this tool works. For this, I will be running this script after transferring it to target Ubuntu 20.04 machine after gaining a shell. The simplest way to run this script is using the command shown below.

./linux exploit suggester

As you can see in the above images, this script found 81 kernel exploits and 49 user space exploits. Moreover. it suggested the vulnerability and also an exploit for this. For example, in this case, the target system is vulnerable to DirtyPipe, Pwnkit vulnerabilities etc.

You can even run Linux exploit suggester by supplying the kernel information as shown below.

You can even supply the entire output of “uname-a” command by using the “-u” option.

Check security settings of the target system (–checksec)

This tool can also check most security settings in your Linux kernel using this option.

View only kernel space exploits

Setting this option shows only kernel related exploits for the target kernel.

View only userspace exploits

Setting this option shows only userspace exploits.

Display sources (-s)

Setting this option not only lists the exploits but also downloads the source code of the exploits.

The sources of the exploit are in the format of zip archive.

Download binaries (-b)

Setting this option downloads binaries of the exploit code if available. Binary exploits can be executed directly.

Get more detailed view (-f)

Setting this option displays a more detailed view of the exploit.

Get a brief view (-g)

Setting this option displays only brief information about found exploits.

After getting the exploit information, all you have to do is execute the exploit to elevate privileges on the target linux system. Next, learn about linux post exploitation after gaining elevated privileges.

Hello, aspiring ethical hackers. In our previous blogpost, you learnt about Linux privilege escalation. In this article, you will learn about UNIX privesc check , a tool that will help you in elevating privileges on a Linux and UNIX system.

UNIX privesc check is a shell script that checks for all simple privilege escalation vectors on a UNIX system. This script finds misconfigurations and other settings that could allow local unprivileged users to elevate privileges on a target Linux system.

Let’s see how this tool works. For this, we will be using Kali Linux as this tool is available by default in its repositories. As target system, we will be using Metasploitable 2 installed in our virtual hacking lab.

As it is a local privilege escalation script, it needs to be run on the target system. Obviously, you need to have access on the target system. Learn various methods to gain access to a Linux system in our Linux hacking article. After gaining access, we can use any method to download the UNIX-privesc-check script to the target system.

Next, it can be executed like any other shell script.

Unix privesc check runs in two modes: standard and detailed. In standard mode it performs a speed optimised check of security settings. It can be run in standard mode as shown below.

./unix-privesc-check standard

In the detailed mode, it performs all checks performed in standard mode but additionally it will also perform checks of permissions of open file handles and other files. This mode sis low but can help you find more weaknesses in 3rd party programs. UNIX privesc check can be run in detailed mode using command shown below.

./unix-privesc-ccheck detailed

It is good practice to save the scan output to a file. This can be done as shown below.

Usually this file with scanned output needs to be transferred to the attacker system for analysis. This can be done using tools like netcat or socat. For example, let’s transfer “detailed_output.txt” file to attacker system for observation. While observing the output file, you need to look out for “warning” signs. These allow in privilege escalation of Linux system.

For example, you can see that SUDO is configured in the above image.

This tool has also found one binary with SUID bit set. Learn about SETUID privilege escalation.

It has even found public and private SSH keys which can be used to login to SSH server on target system. Learn about SSH hacking in our comprehensive guide.

That’s how we use this tool. Learn about Windows privesc check, a tool that helps us in elevating privileges on a Window system.

Hello, aspiring ethical hackers. In this blogpost, you will learn about a tool called Lynis, the security auditing and hardening tool for UNIX based systems like Linux, macOS, BSD and others. It performs an in-depth security scan to test security defenses and provide suggestions for further system hardening.

This tool audits the following features on the system.

1. General system information.
2. System tools.
3. Operating system.
4. Boot and other services.
5. Kernel vulnerabilities.
6. Memory and processes.
7. Users, groups and authentication
8. Kerberos
9. Shells
10. File systems
11. USB devices
12. Storage
13. NFS
14. Name Services
15. Ports and packages
16. Networking
17. Printers and Spool
18. Email and messaging software
19. Firewalls
20. Web servers
21. SSH and SNMP
22. Databases
23. PHP (in web server)
24. Logging and log files
25. Insecure services
26. Banners
27. Scheduled Tasks
28. Accounting
29. Time and synchronization
30. Cryptography
31. Virtualization
32. Containers
33. Security frameworks
34. System tools and malware
35. File permissions etc.

Let’s see how to run Lynis for the first time. For this, we will be using Kali Linux. It can be installed on Kali as shown below.

After the installation is successful, run the command shown below to run it to audit the entire system.

lynis audit system

It runs as shown below.

While auditing, wherever there is scope for hardening, lynis adds a suggestion as shown below.

After the entire system is audited, Lynis provides summary of the entire audit as shown below.

Below the summary, you can find each suggestion as shown below.

You can harden your system based on these suggestions. You can also find this information in the log reports of Lynis.

Hello aspiring ethical hackers. In our previous blogpost, you studied about website footprinting. In this blogpost, you will learn about a tool called eyewitness which helps you to decide which website to focus on.

In ethical hacking, before trying to footprint a website, it would be good if we have a general idea about what websites to target first. For example, a company you are going to pen test may have multiple websites and sub domains. Before we jump into password cracking or exploitation or directory busting or perform any other attack, it would be good if we are first able to decide what website and URLs to target first. The role of eyewitness tool comes there. Eyewitness takes the screenshots of the URLs or websites you provide. Apart from taking screenshot of the URL, it will also capture any header info and default passwords.

Let’s see how to use this tool. For this we will be using Kali Linux as this tool is available by default in Kali repositories. As target, we will be using Metasploitable 2 installed in our virtual hacking Lab. It can be installed as shown below.

Target a single URL (–single)

You can take screenshot of a single URL as shown below.

As soon as it writes a report for your target, it will ask you if you want to open the report. Click on “Yes”. It will open the report as shown below.

You can even view the code of the URL you scanned.

But the real power of eyewitness can be seen when we are targeting multiple URLs at once. For doing this, we will first create a file called URLS.txt and add some URLs we want to target as shown below.

Target multiple URLs (-f)

Multiple URLs can be targeted with this tool by specifying the above created file with (-f) option.

Here’s the report.

One of our URLs we targeted ended up in a error.

Skip DNS resolution(–no-dns)

In some cases, while using eyewitness tool, you may have to go through a VPN. In such cases, it is good to skip DNS resolution when connecting to the website. This option helps you to do it.

Resolve IP / host name for your target (–resolve)

Time to wait while requesting an URL (–timeout)

By default, eyewitness waits for 7 seconds before it goes to take a screenshot of a new webpage. However, this can be changed with this option. For example, let’s change the timeout time to 1 second.

Add jitter (–jitter)

Using this option, we can randomize the URLs specified and add a random delay.

Add delay before taking a screenshot (–delay)

Using the option, we can add delay between opening of the navigator and taking a screenshot. This delay can be specified in seconds. For example, let’s add 10 seconds delay before taking screenshot.

Maximum retries (–max-retries)

This option specifies eyewitness tool how many retries it has to make if it fails to grab a screenshot on the first attempt.

Specify directory name for saving the report (-d)

This option is used to specify a directory name for saving the report.

Number of results to show on one page (–results)

By default, eyewitness shows output for all the URLs given as input on a single page. This option can be used to specify how many results to show per page. For example, let’s set it to show 1 result per page.

As you can see, now, all the results are shown on separate pages.

You don’t want to be prompted for viewing the report (–no-prompt)

If you don’t want eyewitness to prompt you to open the report after finishing its work, you can use this option.