Rule Document 1:718

Rule Category

PROTOCOL-TELNET -- Snort has detected traffic that may indicate the presence of the telnet protocol or vulnerabilities in the telnet protocol on the network.

Alert Message

PROTOCOL-TELNET login incorrect

Rule Explanation

This event is generated when an attempted telnet login fails from a remote user. Impact: Attempted remote access. This event may indicate that an attacker is attempting to guess username and password combinations. Alternately, it may indicate that an authorized user has entered an incorrect username and password combination. Details: A telnet server will issue an error message after a failed login attempt. This may be an indication of an attacker attempting brute force guessing of username and password combinations. It is also possible that an authorized user has incorrectly entered a legitimate username and password combination. Telnet traffic is passed in clear text so it is not recommended for remote connections. Secure Shell is considered to be a more secure alternative. Ease of Attack: Simple

What To Look For

No information provided

Known Usage

No public information

False Positives

Known false positives, with the described conditions

This event may be triggered by a failed telnet login attempt from a remote user.

Contributors

Original rule writer Max Vision <vision@whitehats.com> Documented by Steven Alexander<alexander.s@mccd.edu> Cisco Talos Judy Novak