New Telnet hole affects some Unix-based servers

A security hole discovered in a Unix-based operating system can allow remote hackers to gain complete access to or crash the Web server. It is unclear if all Unix mainstream operating systems are affected.

According to an advisory issued earlier this week by, the vulnerability in the Telnetd program was shipped with all versions -- except the forthcoming 4.4 release -- of FreeBSD's open-source operating systems built on code developed by Berkeley Software Design Inc. Telnetd is the server for the telnet remote virtual terminal protocol.

Other Unix operating systems built on code from Berkeley Software Design, such as BSDI and NetBSD, are also affected.

According to FreeBSD, the Telnet daemon is enabled by default on all FreeBSD installations and is being actively exploited "in the wild." Telnet is an Internet protocol that allows users to log on to a computer terminal from a remote location.

The vulnerability was discovered by the security group TESO, according to the CERT Coordination Center at Pittsburgh-based Carnegie Mellon University's Software Engineering Institute. In an advisory on its Web site yesterday, CERT said Cisco Systems Inc.'s Internetworking Operating System doesn't appear to be vulnerable. CERT said it's unclear if Hewlett Packard's operating system is affected. In addition, CERT said Sun Microsystems Inc. is investigating and has confirmed that a hacker "can make the in.telnetd daemon dump core, but Sun has not yet determined if this issue can be exploited on Solaris."

Join the newsletter!

Error: Please check your email address.
Rocket to Success - Your 10 Tips for Smarter ERP System Selection
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Linda Rosencrance

Show Comments


James Cook University - Master of Data Science Online Course

Learn more >


Sansai 6-Outlet Power Board + 4-Port USB Charging Station

Learn more >



Back To Business Guide

Click for more ›

Brand Post

Most Popular Reviews

Latest Articles


PCW Evaluation Team

Louise Coady

Brother MFC-L9570CDW Multifunction Printer

The printer was convenient, produced clear and vibrant images and was very easy to use

Edwina Hargreaves

WD My Cloud Home

I would recommend this device for families and small businesses who want one safe place to store all their important digital content and a way to easily share it with friends, family, business partners, or customers.

Walid Mikhael

Brother QL-820NWB Professional Label Printer

It’s easy to set up, it’s compact and quiet when printing and to top if off, the print quality is excellent. This is hands down the best printer I’ve used for printing labels.

Ben Ramsden

Sharp PN-40TC1 Huddle Board

Brainstorming, innovation, problem solving, and negotiation have all become much more productive and valuable if people can easily collaborate in real time with minimal friction.

Sarah Ieroianni

Brother QL-820NWB Professional Label Printer

The print quality also does not disappoint, it’s clear, bold, doesn’t smudge and the text is perfectly sized.

Ratchada Dunn

Sharp PN-40TC1 Huddle Board

The Huddle Board’s built in program; Sharp Touch Viewing software allows us to easily manipulate and edit our documents (jpegs and PDFs) all at the same time on the dashboard.

Featured Content

Product Launch Showcase

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?