About Cisco Type 7 Password Encryption
What is Type 7 Encryption? Cisco Type 7 is a simple obfuscation method, not true encryption. It was designed in the 1980s to prevent casual observation of passwords in configuration files, but it provides no real security against determined attackers.
How Type 7 "Encryption" Works:
- Fixed Salt: Type 7 uses a hardcoded constant string: "dsfd;kfoA,.iyewrkldJKDHSUBsgvca69834ncxv9873254k;fg87"
- Index Selection: The first two digits of the encrypted string indicate which character in the salt to start with (0-52)
- XOR Operation: Each character of the password is XORed with successive characters from the salt
- Hex Encoding: The XOR results are converted to hexadecimal pairs and concatenated
Why Type 7 is Insecure:
- The algorithm was reverse-engineered and published in 1995
- The salt is publicly known and never changes
- It's a simple XOR cipher, not cryptographic encryption
- Can be cracked instantly with readily available tools
- Provides zero protection against anyone with access to the configuration
Attack Vectors:
- SNMP Access: Attackers can query network devices via SNMP to retrieve configurations
- Backup Server Compromise: TFTP, FTP, or SCP servers storing backups may be vulnerable
- Email Interception: TAC communications often include configurations
- Insider Threats: Anyone with read access to configs can decrypt passwords
✓ Recommended Solutions:
- Type 5 (MD5): Use "enable secret" instead of "enable password" - provides one-way MD5 hashing
- Type 8 (PBKDF2-SHA256): Modern password-based key derivation (available on newer IOS versions)
- Type 9 (scrypt): Most secure option, resistant to hardware-based attacks (IOS-XE 16.9+)
- AAA/TACACS+: Centralize authentication and use stronger protocols
- Secure Transport: Always use SSH instead of Telnet, HTTPS instead of HTTP
Defense in Depth:
Even with proper password encryption, implement these security measures:
- Use Control Plane Policing (CoPP) to protect management plane
- Implement Access Control Lists (ACLs) to restrict management access
- Secure SNMP with strong community strings and ACLs (or disable if unused)
- Protect configuration backup servers with proper authentication and encryption
- Use DNSSEC to prevent DNS poisoning attacks
- Implement least-privilege access and regularly rotate credentials
References:
Educational Purpose:
This tool is provided for educational purposes and authorized security testing only. It demonstrates the weakness of outdated cryptographic methods and highlights the importance of using modern, secure authentication mechanisms. Never use this tool for unauthorized access to systems.