SSH (Secure Shell) and Telnet

SSH (Secure SHell)

  • Developed by SSH Communications Security Ltd., SSH is now the primary protocol for accessing network devices and servers over the internet.
  • It allows users to log into remote computers, execute commands, and transfer files securely.
  • SSH provides strong authentication and secure communication over insecure channels, using encryption to ensure data confidentiality.
  • SSH runs on port 22 by default but can be changed, protecting against attacks like IP spoofing and DNS spoofing.
  • It uses public key authentication, which is highly secure.
  • Supported by major operating systems such as Unix, Solaris, Red-Hat Linux, CentOS, and Ubuntu.
  • Offers secure login sessions, encrypted data transfer, and secure file movements.
  • Common clients include built-in terminal for Mac OS X & Linux, PuTTY for Windows, JuiceSSH for Android, and Prompt for iOS.

Telnet

  • An older protocol launched alongside the internet in 1969, Telnet allows remote system communication and was crucial in early networking for remote login to mainframes.
  • Runs on port 23 and is designed for local area networks.
  • Transfers data in plain text, making it insecure for use over public networks.
  • Telnet is suitable for trusted private networks or devices that don’t support SSH.
  • Lacks data encryption and authentication mechanisms, making it vulnerable to security threats.
  • Mainly used today by purists or in specific trusted network scenarios.

Key Differences between SSH and Telnet

  • Security: SSH encrypts data, while Telnet sends data in plain text.
  • Authentication: SSH uses public key authentication; Telnet does not.
  • Usage: SSH is suitable for public networks; Telnet is for private, trusted networks.
  • Functionality: SSH allows remote command execution and secure data transfer; Telnet does not support these features.
  • Port: SSH uses port 22 by default; Telnet uses port 23.

When to Use

  • Telnet: Use on trusted networks (e.g., LANs) not connected to the internet or with devices that don't support SSH.
  • SSH: Use for secure connections over the internet, offering secure file transfers and port forwarding.

Advantages

  • Advantages of Telnet: User authentication, collaboration of multiple users, saves research time.
  • Advantages of SSH: Free for non-commercial use, strong authentication, secure communications, supports tunneling of insecure applications, provides privacy and integrity of data.

Disadvantages

  • Telnet: Not ideal for transmitting GUI information, no encryption, port number vulnerabilities, text-only display.
  • SSH: Not designed to transmit GUI information, doesn't fix all TCP problems, doesn’t protect against all types of attacks.

Conclusion

Telnet and SSH serve similar purposes in enabling remote system management, but SSH offers significantly better security through encryption and public key authentication, making it the preferred choice for most modern applications over unsecured networks.

Comments

Post a Comment

Popular posts from this blog

What is the CIA Triad?

The CIA Triad stands for Confidentiality, Integrity, and Availability. This model is fundamental in developing security systems, identifying vulnerabilities, and creating solutions. The CIA Triad segments these three crucial aspects, guiding security teams to address each concern effectively. When all three standards are met, an organization's security profile is stronger and better equipped to handle threats. 1. Confidentiality Confidentiality ensures that data is kept secret or private. It involves controlling access to prevent unauthorized data sharing. Only individuals with proper authorization should access sensitive business information. For example, employees managing finances should access relevant spreadsheets and bank accounts, while others should not. Confidentiality breaches can occur through direct attacks like man-in-the-middle (MITM) attacks, where attackers intercept and alter data. Other breaches result from human error, such as failing to protect passwords or shar...
Read more

What is SQL Injection (SQLi)?

SQL Injection (SQLi) is a critical web security vulnerability where attackers manipulate input to interfere with an application's database queries. This allows unauthorized access to sensitive data, alteration of database content, or even compromising the underlying server. Impact of a Successful SQL Injection Attack A successful SQLi attack can lead to unauthorized access to sensitive information such as passwords, credit card details, and personal user data. It has been involved in numerous high-profile data breaches, resulting in reputational damage, regulatory fines, and long-term compromises of organizational systems. Detection of SQL Injection Vulnerabilities SQL Injection vulnerabilities can be manually detected by testing each entry point in the application: Use characters like ' to detect errors or anomalies. Test SQL-specific syntax to compare responses. Employ Boolean conditions (e.g., OR 1=1) to identify differences in application responses. Use payloads triggering...
Read more

Threat, Vulnerability, and Risk: What’s the Difference?

 Vulnerabilities: A vulnerability in cybersecurity refers to any weakness or flaw in the design, implementation, configuration, or management of an asset that could potentially be exploited by a threat actor to compromise the confidentiality, integrity, or availability of that asset. These vulnerabilities can exist at various levels: they might be technical in nature, such as software bugs or misconfigurations in network devices; they could also be human-related, such as employees falling victim to phishing attacks or unintentionally exposing sensitive information. For example, leaving sensitive data unprotected on a server without adequate access controls constitutes a vulnerability. Identifying vulnerabilities is crucial for cybersecurity professionals because it allows them to proactively address and mitigate potential risks before they are exploited by malicious actors. Regular vulnerability assessments, penetration testing, and security audits are common practices used to iden...
Read more