COMMAND
protected password database
SYSTEMS AFFECTED
Digital Unix 4X
PROBLEM
James Clement found following. Due to the recent outpouring of DU
buffer overflows the following might be of interest. With the
Enhanced Security package running, authentication info is stored
in individual files according to username. In this case
/tcb/files/auth/r/root for root and so on. Being not aware of any
built in method for creating the equivalent of your everyday unix
/etc/shadow file as a result it is probable that many DU systems
have not weeded out poor choices for passwords through the use of
a program such as Crack since each encrypt is stored in a separate
file. Though trivial once root is compromised, a would be
attacker might have an easy time obtaining passwords because of
this "feature". The program below outputs a crackable shadow
file.
/*
Digital Unix 4.x get encrypts from protected password database(s).
Must be euid(0), compile with cc dushad.c -lsecurity -o dushad
Written by James Clement - clem7508@fredonia.edu
*/
#include <sys/types.h>
#include <sys/security.h>
#include <prot.h>
struct pr_passwd *getprpwent(void);
void main(){
struct pr_passwd *p;
set_auth_parameters();
while (p = getprpwent())
{
printf("%s:%s:%d:::\n", p->ufld.fd_name, p->ufld.fd_encrypt, p->ufld.fd_uid);
}
}
The one thing that a lot of people miss with Digital UNIX is that
when you use Enhanced Security in conjunction with NIS, the entire
"protected" password subsystem is available as the NIS map
prpasswd. This contains, amongst other things, the password hash
value. The one thing that CAN cause problems is that Digital
UNIX can use nonstandard hash algorithms (bigcrypt(), crypt16()
and C1crypt()) as well as the normal crypt(). Not only does this
make coding slightly complicated (as you have to get the correct
hash algorithm, but when a password is created within an Enhanced
Security environment that is over eight characters in length,
another password round is created AFTER the original to contain
the rest of the password. This doesn't make things impossible,
just difficult - Digital kindly provide a set of system calls to
do most of this for you.
SOLUTION
Well, keep up your system and no reason to be scared.