# Telnet: 23

#### **Security Weaknesses**

* Transmits all data, including credentials, in plaintext.
* Susceptible to MITM (man-in-the-middle) attacks.
* Deprecated and insecure for modern use.

#### **Security Defense and Mitigation Measures**

* Replace Telnet with SSH for secure remote access.
* Disable Telnet services on servers and devices.
* Monitor for any unencrypted traffic on port 23 (TCP).

#### **Indicators of Compromise or Attack**

* Active Telnet sessions or unencrypted traffic on port 23.
* Failed login attempts indicating brute force attacks.
* Unauthorized system changes made via Telnet sessions.
