LinuxQuestions.org
Visit the LQ Articles and Editorials section
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Software
User Name
Password
Linux - Software This forum is for Software issues.
Having a problem installing a new program? Want to know which application is best for the job? Post your question in this forum.

Notices

Reply
 
Search this Thread
Old 10-22-2001, 11:35 AM   #1
adamrau
Member
 
Registered: Sep 2001
Posts: 42

Rep: Reputation: 15
SENDMAIL - How to prevent telnet into my server on port 25


Hi,
I have removed my telnet package and still people from the outside can telnet myhost.mydomain.com 25 and see my version/etc of sendmail. I thought removing my telnet package would fix this, it didnt. Does anyone know how I could prevent people from telneting in on port 25. I even have telnet disabled, but for some reason telnet on port 25 is still allowed.

Thanks in advance
Adam
 
Old 10-22-2001, 11:46 AM   #2
acid_kewpie
Moderator
 
Registered: Jun 2001
Location: UK
Distribution: Gentoo, RHEL, Fedora, Centos
Posts: 43,415

Rep: Reputation: 1968Reputation: 1968Reputation: 1968Reputation: 1968Reputation: 1968Reputation: 1968Reputation: 1968Reputation: 1968Reputation: 1968Reputation: 1968Reputation: 1968
you've definitely set

disable = yes

in the xinetd telnet file?
 
Old 10-22-2001, 01:50 PM   #3
adamrau
Member
 
Registered: Sep 2001
Posts: 42

Original Poster
Rep: Reputation: 15
Hi,
Im absolutely positive. Im using RedHat 7.1 and disabling telnet is by default.
I find it very strange to have telnet disabled and yet its not really fully diabled.

Thanks
Adam
 
Old 04-19-2010, 04:04 PM   #4
d3adpoetic
LQ Newbie
 
Registered: Mar 2010
Posts: 19

Rep: Reputation: 0
does this help??

http://www.webhostgear.com/74.html
 
Old 04-19-2010, 08:17 PM   #5
chrism01
Guru
 
Registered: Aug 2004
Location: Sydney
Distribution: Centos 6.6, Centos 5.10
Posts: 16,324

Rep: Reputation: 2041Reputation: 2041Reputation: 2041Reputation: 2041Reputation: 2041Reputation: 2041Reputation: 2041Reputation: 2041Reputation: 2041Reputation: 2041Reputation: 2041
There's the telnet server SW, which you claim to have removed; check

rpm -qa |grep -v telnetd


and the telnet client SW which other people have. There's nothing you can do about that. Any service that runs in plain ascii text eg mail on port 25 can be interrogated by a remote telnet client.
Good for debugging eg try telnetting to port 80 on a server that's running Apache...
You may be be able to set a flag in sendmail to suppress the version num if you're paranoid, but its a minor thing in the larger picture of security.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
redhat 9: sendmail port 25 not allowing outside telnet aagha Linux - Networking 4 08-29-2003 12:23 AM
How to prevent X server from opening port 6000 glock19 Linux - General 5 05-23-2002 04:19 PM
sendmail telnet port frieza Linux - Networking 2 03-06-2002 05:26 PM
How to prevent telneting to my mail server on port 25 adamrau Linux - Networking 7 10-24-2001 10:44 PM
How to prevent someone from telneting to my mail server on port 25 adamrau Linux - Security 2 10-11-2001 03:33 PM


All times are GMT -5. The time now is 07:49 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration