[Dovecot] dovecot under attack

Charles Marcus CMarcus at Media-Brokers.com
Sat Jun 16 17:23:42 EEST 2007


Hi Jon,

I cannot help with the specific question, but in my opinion, your first 
and primary goal should be to get that server updated to 1.0.1 asap...

0.99.x is no longer supported - and *very* dated...

Jon Slater wrote:
> Hi,
> 
>  
> 
> I’ve posted this before but no one was able to help.  I can’t figure out
> what they are trying to do, and if I should be concerned.
> 
>  
> 
> I am running dovecot version 0.99.14 on Fedora Core 4.  It appears that my
> dovecot server is under attack.  This morning in my system e-mail I saw
> this:
> 
> 
> 
>      dovecot:
> 
>          Authentication Failures:
> 
>              rhost= : 23431 Time(s)
> 
>             adm: 33 Time(s)
> 
>             bin: 33 Time(s)
> 
>             mail: 33 Time(s)
> 
>             mysql: 21 Time(s)
> 
>             nobody: 15 Time(s)
> 
>             news: 14 Time(s)
> 
>             operator: 8 Time(s)
> 
>             sshd: 2 Time(s)
> 
>          Unknown Entries:
> 
>             check pass; user unknown: 23431 Time(s)
> 
>  
> 
> But, when I check my log files I can’t find an IP address for the attacker.
> So, for example, if I search my logs for “operator” I see:
> 
> ./messages:Jun 15 23:30:56 lambdacenter dovecot(pam_unix)[15512]:
> authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=
> user=operator
> 
> ./messages:Jun 15 23:31:00 lambdacenter dovecot(pam_unix)[15670]:
> authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=
> user=operator
> 
> ./messages:Jun 15 23:31:16 lambdacenter dovecot(pam_unix)[16332]:
> authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=
> user=operator
> 
> ./messages:Jun 15 23:31:20 lambdacenter dovecot(pam_unix)[16480]:
> authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=
> user=operator
> 
> ./messages:Jun 15 23:31:27 lambdacenter dovecot(pam_unix)[16695]:
> authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=
> user=operator
> 
> ./messages:Jun 15 23:31:38 lambdacenter dovecot(pam_unix)[16884]:
> authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=
> user=operator
> 
> ./messages:Jun 15 23:31:55 lambdacenter dovecot(pam_unix)[17080]:
> authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=
> user=operator
> 
> ./messages:Jun 15 23:32:11 lambdacenter dovecot(pam_unix)[17182]:
> authentication failure; logname= uid=0 euid=0 tty= ruser= rhost=
> user=operator
> 
> ./audit/audit.log:type=USER_AUTH msg=audit(1181971858.967:156312): user
> pid=15512 uid=0 auid=4294967295 msg='PAM authentication: user=operator
> exe="/usr/libexec/dovecot/dovecot-auth" (hostname=?, addr=?, terminal=?
> result=Authentication failure)'
> 
> ./audit/audit.log:type=USER_AUTH msg=audit(1181971862.772:156382): user
> pid=15670 uid=0 auid=4294967295 msg='PAM authentication: user=operator
> exe="/usr/libexec/dovecot/dovecot-auth" (hostname=?, addr=?, terminal=?
> result=Authentication failure)'
> 
> ./audit/audit.log:type=USER_AUTH msg=audit(1181971878.710:156707): user
> pid=16332 uid=0 auid=4294967295 msg='PAM authentication: user=operator
> exe="/usr/libexec/dovecot/dovecot-auth" (hostname=?, addr=?, terminal=?
> result=Authentication failure)'
> 
> ./audit/audit.log:type=USER_AUTH msg=audit(1181971882.379:156775): user
> pid=16480 uid=0 auid=4294967295 msg='PAM authentication: user=operator
> exe="/usr/libexec/dovecot/dovecot-auth" (hostname=?, addr=?, terminal=?
> result=Authentication failure)'
> 
> ./audit/audit.log:type=USER_AUTH msg=audit(1181971908.712:156879): user
> pid=16695 uid=0 auid=4294967295 msg='PAM authentication: user=operator
> exe="/usr/libexec/dovecot/dovecot-auth" (hostname=?, addr=?, terminal=?
> result=Authentication failure)'
> 
> ./audit/audit.log:type=USER_AUTH msg=audit(1181972032.080:156904): user
> pid=16884 uid=0 auid=4294967295 msg='PAM authentication: user=operator
> exe="/usr/libexec/dovecot/dovecot-auth" (hostname=?, addr=?, terminal=?
> result=Authentication failure)'
> 
> ./audit/audit.log:type=USER_AUTH msg=audit(1181972047.607:156917): user
> pid=17080 uid=0 auid=4294967295 msg='PAM authentication: user=operator
> exe="/usr/libexec/dovecot/dovecot-auth" (hostname=?, addr=?, terminal=?
> result=Authentication failure)'
> 
> ./audit/audit.log:type=USER_AUTH msg=audit(1181972066.325:156928): user
> pid=17182 uid=0 auid=4294967295 msg='PAM authentication: user=operator
> exe="/usr/libexec/dovecot/dovecot-auth" (hostname=?, addr=?, terminal=?
> result=Authentication failure)'
> 
>  
> 
> I’ve checked my snmplog for port activity on port 110 (for POP3) and 143
> (for IMAP), but I don’t see anything unusual.  I also systematically
> filtered out everything I knew was okay (ssh, and httpd) .
> 
>  
> 
> Does anyone know what this is?  Or someone I could ask?
> 
>  
> 
> Thanks!!!!!!!!!!!!!!!!!!!!
> 
>  
> 
> Jon
> 
> 
> No virus found in this outgoing message.
> Checked by AVG Free Edition. 
> Version: 7.5.472 / Virus Database: 269.8.17/850 - Release Date: 6/15/2007
> 11:31 AM
>  
> 




More information about the dovecot mailing list