Default Port: 49
TACACS (Terminal Access Controller Access-Control System) is a protocol used to manage access to network devices and servers. TACACS+ is a more secure and advanced version that provides authentication, authorization, and accounting.
Connect
Connect Using TACACS Client
You can connect to a TACACS server using a TACACS client. For example, on Linux systems, you can use the TACACS client with the following command:
tacacs_client -u <username> -p <password> -a <TACACS-server-ip>
This command allows you to connect to a specific TACACS server with a given username and password.
Recon
Identifying a TACACS Server
You can use Nmap to check if there is a TACACS service running on a specific host:
nmap -p 49 X.X.X.X
This command checks if there is a service running on port 49 of the specified IP address.
Banner Grabbing
You can use Netcat or a similar tool to perform banner grabbing and retrieve information about the TACACS service:
nc -nv X.X.X.X 49
This command collects banner information from the service running on port 49 of the given IP address.
Enumeration
TACACS+ Packet Analysis
You can use packet analysis tools like Wireshark to capture and analyze TACACS+ packets. TACACS+ traffic operates over TCP port 49.
Enumerating TACACS Users
There may be methods to enumerate TACACS users and groups, although it typically requires proper authorization. If you gain access, you can attempt to retrieve user and group details.
Attack Vectors
Default Credentials
Check for default credentials or weak authentication configurations. For example, try common password combinations like admin:admin123 or admin:<blank>.
Brute Force Attacks
You can perform brute-force attacks to guess weak passwords using tools like hydra:
hydra -l admin -P /path/to/passwords.txt <target_ip> -s 49 tacacs
Unauthorized Access
Exploit misconfigured access controls or weak authentication mechanisms to gain unauthorized access.
Post-Exploitation
Privilege Escalation
After gaining unauthorized access, try various methods to escalate privileges to higher-level accounts.
Data Analysis and Manipulation
Once you have access to sensitive data on network devices, you can analyze or manipulate this data.
User Session Hijacking
Target and hijack active user sessions to capture session information and manipulate sessions to your advantage.
Example of TACACS CLI Commands (Hypothetical)
Command| Description
---|---
tacacs_client -l <entity>| List entities like users or sessions.
tacacs_client -i <entity>\ -u <user>| Display detailed information about a specific user.
tacacs_client -a <entity>\ -n <name>| Add a new user/entity to TACACS.
tacacs_client -d <entity>\ -u <user>| Delete an existing user/entity from TACACS.
These commands are typically used for managing TACACS, and you can use them after gaining unauthorized access.