[gentoo-user] Can't block pop3 attack

[gentoo-user] Can't block pop3 attack

[Robin Atwood]

My syslog is showing zillions of messages:

Oct 24 02:25:58 opal xinetd[8054]: START: pop-3 pid=16534 from=61.134.64.199
Oct 24 02:25:59 opal xinetd[16534]: warning: /etc/hosts.allow, line 7: can't 
verify hostname: gethostbyname(199.64.134.61.broad.gs.dynamic.163data.com.cn) 
failed
Oct 24 02:26:09 opal xinetd[8054]: EXIT: pop-3 status=0 pid=16534 
duration=11(sec)

I run denyhosts but don't trap pop3 messages so I manually added the IP 
address to /etc/hosts.deny and..., it made absolutely no difference. I run 
qpopper which is compiled with xinetd support and xinetd uses tcpd, so I 
assumed the address would be blocked. Apparently not so. Any ideas?

TIA
-Robin
-- 
----------------------------------------------------------------------
Robin Atwood.

"Ship me somewheres east of Suez, where the best is like the worst,
 Where there ain't no Ten Commandments an' a man can raise a thirst"
         from "Mandalay" by Rudyard Kipling
----------------------------------------------------------------------

Re: [gentoo-user] Can't block pop3 attack

[Alan McKinnon]

On Friday 23 October 2009 21:49:42 Robin Atwood wrote:
> My syslog is showing zillions of messages:
> 
> Oct 24 02:25:58 opal xinetd[8054]: START: pop-3 pid=16534
>  from=61.134.64.199 Oct 24 02:25:59 opal xinetd[16534]: warning:
>  /etc/hosts.allow, line 7: can't verify hostname:
>  gethostbyname(199.64.134.61.broad.gs.dynamic.163data.com.cn) failed
> Oct 24 02:26:09 opal xinetd[8054]: EXIT: pop-3 status=0 pid=16534
> duration=11(sec)
> 
> I run denyhosts but don't trap pop3 messages so I manually added the IP
> address to /etc/hosts.deny and..., it made absolutely no difference. I run
> qpopper which is compiled with xinetd support and xinetd uses tcpd, so I
> assumed the address would be blocked. Apparently not so. Any ideas?


You have allow ALL ALL early in hosts.allow, or
you have allow pop3 all earlier in hosts.allow 

-- 
alan dot mckinnon at gmail dot com

Re: [gentoo-user] Can't block pop3 attack

[Robin Atwood]

On Saturday 24 October 2009, Alan McKinnon wrote:
> On Friday 23 October 2009 21:49:42 Robin Atwood wrote:
> > My syslog is showing zillions of messages:
> >
> > Oct 24 02:25:58 opal xinetd[8054]: START: pop-3 pid=16534
> >  from=61.134.64.199 Oct 24 02:25:59 opal xinetd[16534]: warning:
> >  /etc/hosts.allow, line 7: can't verify hostname:
> >  gethostbyname(199.64.134.61.broad.gs.dynamic.163data.com.cn) failed
> > Oct 24 02:26:09 opal xinetd[8054]: EXIT: pop-3 status=0 pid=16534
> > duration=11(sec)
> >
> > I run denyhosts but don't trap pop3 messages so I manually added the IP
> > address to /etc/hosts.deny and..., it made absolutely no difference. I
> > run qpopper which is compiled with xinetd support and xinetd uses tcpd,
> > so I assumed the address would be blocked. Apparently not so. Any ideas?
> 
> You have allow ALL ALL early in hosts.allow, or
> you have allow pop3 all earlier in hosts.allow
 
The second! I had forgotten about that. The trouble I set it up that way so I 
could pick up email from arbitrary locations while travelling. It seems the 
price of that is allowing idiots to spam your logs. 

Thanks for the pointer.
-Robin
-- 
----------------------------------------------------------------------
Robin Atwood.

"Ship me somewheres east of Suez, where the best is like the worst,
 Where there ain't no Ten Commandments an' a man can raise a thirst"
         from "Mandalay" by Rudyard Kipling
----------------------------------------------------------------------

Re: [gentoo-user] Can't block pop3 attack

[kashani]

Robin Atwood wrote:
> On Saturday 24 October 2009, Alan McKinnon wrote:
>> On Friday 23 October 2009 21:49:42 Robin Atwood wrote:
>>> My syslog is showing zillions of messages:
>>>
>>> Oct 24 02:25:58 opal xinetd[8054]: START: pop-3 pid=16534
>>>  from=61.134.64.199 Oct 24 02:25:59 opal xinetd[16534]: warning:
>>>  /etc/hosts.allow, line 7: can't verify hostname:
>>>  gethostbyname(199.64.134.61.broad.gs.dynamic.163data.com.cn) failed
>>> Oct 24 02:26:09 opal xinetd[8054]: EXIT: pop-3 status=0 pid=16534
>>> duration=11(sec)
>>>
>>> I run denyhosts but don't trap pop3 messages so I manually added the IP
>>> address to /etc/hosts.deny and..., it made absolutely no difference. I
>>> run qpopper which is compiled with xinetd support and xinetd uses tcpd,
>>> so I assumed the address would be blocked. Apparently not so. Any ideas?
>> You have allow ALL ALL early in hosts.allow, or
>> you have allow pop3 all earlier in hosts.allow
>  
> The second! I had forgotten about that. The trouble I set it up that way so I 
> could pick up email from arbitrary locations while travelling. It seems the 
> price of that is allowing idiots to spam your logs. 
> 
> Thanks for the pointer.
> -Robin

You might think about moving to pop3-ssl or imap-ssl and dropping the 
unencrypted protocols. Usually keeps people from banging on the servers 
and much safer if you use the occasional unsecured wireless network.

kashani