Am 17.10.2011 17:16, schrieb Simon Brereton:
Hi
This is a new one on me - I've never seen spammers attempt to use to SASL Auth to inject spam. None of the users they are trying (newsletter, dummy, test, etc.) exist, but what worries me is the illegal chars error - is this a known vulnerability in dovecot they are trying to exploit? I'm running 1:1.2.15-7 installed from apt-get..
Oct 17 15:07:16 mail postfix/smtpd[14422]: connect from unknown[208.86.147.92] Oct 17 15:07:16 mail dovecot: auth(default): passdb(newsletter@mydomain.net,208.86.147.92): Attempted login with password having illegal chars Oct 17 15:07:17 mail dovecot: pop3-login: Disconnected (auth failed, 1 attempts): user=<test@mydomain.net>, method=PLAIN, rip=208.86.147.92, lip=83.170.64.84 Oct 17 15:07:18 mail postfix/smtpd[14403]: warning: 208.86.147.92: hostname default-208-86-147-92.nsihosting.net verification failed: Name or service not known
Simon
this maybe a brute force attack,or more easy someone missconfigured his client , you may use fail2ban etc to block it not directly related to dovecot
Best Regards
MfG Robert Schetterer
Germany/Munich/Bavaria