Hello, I've reported DoS probrems on Internet Anywhere Mail Server Ver.3.1.3 to support@tnsoft.com on 3rd Dec,99. They started to develop the fix. But they said "we'll release the fix in couple of weeks" three times. I've discussed with Jeff Moll(President of True North Software, Inc.) and he allowed me to post these vulnerabilities. 1. RETR DoS in POP service +OK POP3 Welcome to somewhere.domain using the Internet Anywhere Mail Server Version: 3.1.3. Build: 1065 by True North Software, Inc. USER yellow +OK valid PASS pikapika +OK Authorized RETR 111111111111111111111111 That's all. The Server could be dead at a little bit after atoi(). They should check return value of atoi(). 2. multiple connections to port 25 DoS This is simple game, too. Too much connect()s about 3000, then you will see connection refused. After that, too much connect()s again about 800, then you can't connect anymore. It depends on memory size(I tested on 128MB RAM,total 256MB). They should check connection status. Moderator of BUGTRAQ-JP n-miwa@lac.co.jp ( @ @ ) http://www.lac.co.jp/security/ -------------------------------o00o--(. .)--o00o-------------------------