Red Hat Bugzilla – Bug 837858
iptables should contain default rule to block ssh break-in-attepts
Last modified: 2015-02-17 09:19:59 EST
Description of problem:
Any host with port 22 exposed to the internet will eventually fall victim to the SSH-port scanners, and break in attempt via dictionary of user names and password will eventually happen.
I assume that these break-in attempts are reasonably successful, given the number of scans and the short time from a host goes live to being scanned.
They can reasonably easy be defended against by adding iptables with something like;
-A INPUT -p tcp --dport 22 -m state --state NEW -m recent --set --name SSH
-A INPUT -p tcp --dport 22 -m state --state NEW -m recent --update --seconds 600 --hitcount 5 --rttl --name SSH -j DROP
-A INPUT -p tcp --dport 22 -j ACCEPT
-A INPUT -p tcp -m state --dport 22 --state NEW -j SSH_CHECK
-A SSH_CHECK -m recent --set --name SSH
-A SSH_CHECK -m recent -j DROP --update --seconds 120 --hitcount 9 --name SSH
I would suggest some version of blocking was added to the iptables by default.
Version-Release number of selected component (if applicable): All
This bug appears to have been reported against 'rawhide' during the Fedora 19 development cycle.
Changing version to '19'.
(As we did not run this process for some time, it could affect also pre-Fedora 19 development
cycle bugs. We are very sorry. It will help us with cleanup during Fedora 19 End Of Life. Thank you.)
More information and reason for this action is here:
This message is a notice that Fedora 19 is now at end of life. Fedora
has stopped maintaining and issuing updates for Fedora 19. It is
Fedora's policy to close all bug reports from releases that are no
longer maintained. Approximately 4 (four) weeks from now this bug will
be closed as EOL if it remains open with a Fedora 'version' of '19'.
Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version'
to a later Fedora version.
Thank you for reporting this issue and we are sorry that we were not
able to fix it before Fedora 19 is end of life. If you would still like
to see this bug fixed and are able to reproduce it against a later version
of Fedora, you are encouraged change the 'version' to a later Fedora
version prior this bug is closed as described in the policy above.
Although we aim to fix as many bugs as possible during every release's
lifetime, sometimes those efforts are overtaken by events. Often a
more recent Fedora release includes newer upstream software that fixes
bugs or makes them obsolete.
Fedora 19 changed to end-of-life (EOL) status on 2015-01-06. Fedora 19 is
no longer maintained, which means that it will not receive any further
security or bug fix updates. As a result we are closing this bug.
If you can reproduce this bug against a currently maintained version of
Fedora please feel free to reopen this bug against that version. If you
are unable to reopen this bug, please file a new report against the
current release. If you experience problems, please add a comment to this
Thank you for reporting this bug and we are sorry it could not be fixed.