Re: FreeBSD 2.2.5 Security problem

From: User NEAL (nealat_private)
Date: Sun Jan 03 1999 - 16:16:07 PST

  • Next message: Jason Young: "Re: FreeBSD 2.2.5 Security problem"

    Read the source, Luke!  A login is allowed at most 10 attempts.  After the
    third attempt, a backoff starts up.  After the tenth, the login fails and
    is logged. Look in the source /usr/src/usr.bin/login/login.c, line 523:
    
                    (void)printf("Login incorrect\n");
                    failures++;
    
                    /*
                     * we allow up to 'retry' (10) tries,
                     * but after 'backoff' (3) we start backing off
                     */
                    if (++cnt > backoff) {
                            if (cnt >= retries) {
                                    badlogin(username);
                                    sleepexit(1);
                            }
                            sleep((u_int)((cnt - backoff) * 5));
                    }
    
    
    This code has been in there since 2.2.1 at least(I didn't check back
    farther).
    A simple test verified this behaviour.  After ten login attempts, I was
    booted off and it was dutifully logged:
    Jan  3 16:17:06 <myhost> login: 10 LOGIN FAILURES FROM localhost
    Jan  3 16:17:06 <myhost> login: 10 LOGIN FAILURES FROM localhost, root
    
    
    On Sat, 2 Jan 1999, Missouri FreeNet Administration wrote:
    
    > Greetings, how is everyone after the 30 day pig-out? ;-0
    >
    > We originally posted this problem to the FreeBSD GNATS system on
    > December 20th, and still haven't heard so much as an acknowledgement
    > of the report (GNATS#: i386/9141).  I figured with the holidays, they
    > were all busy, and would [eventually] get to it, but today I checked
    > and saw that several GNATS reports on either side of this one (some
    > as recent as today) have been looked at, processed, and even closed!
    > So...
    >
    > FreeBSD 2.2.5-R (other rev's not tested) fail to log penetration attempts
    > on quiescent systems properly when using syslog (to any target).  Failed
    > login attempts (*any* number of them) will not be reported until a user name
    > which is *different* from the failed name is entered.  For example, I can
    > attempt to penetrate the root password *all day long* without getting a
    > syslog report, provided a name other than root is not entered.  The reson
    > for this is that there is an attempt to de-verbosify syslog reporting in
    > FBSD which accumulates a counter for events, and then reports a cumulative
    > total.  In this attempt to save verbiage, they are tallying all the failed
    > attempts, *rather* than *reporting* them!
    >
    > This is (obviously) not going to be an issue on a busy system, as
    > *someone* other than the target account is likely to log in and flush the
    > counter report, but on a selected system, such as a name server, this
    > could be a devastating flaw...
    >
    >
    > Yours,
    > J.A. Terranson
    > sysadminat_private
    >
    > --
    > If Governments really want us to behave like civilized human beings, they
    > should give serious consideration towards setting a better example:
    > Ruling by force, rather than consensus; the unrestrained application of
    > unjust laws (which the victim-populations were never allowed input on in
    > the first place); the State policy of justice only for the rich and
    > elected; the intentional abuse and occassionally destruction of entire
    > populations merely to distract an already apathetic and numb electorate...
    > This type of demogoguery must surely wipe out the fascist United States
    > as surely as it wiped out the fascist Union of Soviet Socialist Republics.
    >
    > The views expressed here are mine, and NOT those of my employers,
    > associates, or others.  Besides, if it *were* the opinion of all of
    > those people, I doubt there would be a problem to bitch about in the
    > first place...
    > --------------------------------------------------------------------
    >
    



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