[Full-disclosure] Security Alert - The OS X Zombies

From: Thomas Hardly (hardmac_at_gmail.com)
Date: 03/30/05

  • Next message: Tim O'Guin: "Re: [Full-disclosure] Hacked: Who Else Is Using Your Computer?"
    Date: Tue, 29 Mar 2005 15:39:11 -0800
    To: full-disclosure@lists.grok.org.uk
    
    

    http://members.lycos.co.uk/hardapple/
    http://members.lycos.co.uk/hardapple/txt/OSX_Zombies.txt

    ------------------
    >From CLIXchange, the newsletter of the developers of CLIX
    (http://www.rixstep.com/4/0/clix/). ( 3/24/05 ) Also publishers of the
    Mac-X newsletter.

    Quote:
    ----------------------------------------
    SECURITY ALERT
    ----------------------------------------
    [01] The OS X Zombies

    This is important enough to publish here for those who do not receive Mac-X.

    A number of OS X boxes have in fact been compromised. Please read on.

    *

    A certain institution of higher learning has discovered that fleets of
    their OS X boxes have been compromised. They do not yet know the
    vector of attack, meaning it is officially a 'zero day exploit'. They
    do however have several theories - all of which have to do with file
    sharing, anonymous FTP, and root logins over SSH.

    The OS X boxes, when compromised, end up running rogue IRC bot
    controllers and FTP servers. Naturally these rogue processes are
    capable of accessing sensitive data - which can be destroyed,
    modified, or stolen.

    Some of the victimised boxes were exploited through weak passwords for
    SSH-enabled accounts; still others through their Apache servers.
    Apache needs to be patched too and Apple have the patches out there
    for their contribution to the Apache community and they should be
    downloaded. Worse: if the holes in Apache are publicised and the
    sysadmins do not download them, the script kiddies will know how to
    attack.

    [Which all is hardly news for beleaguered Windows system administrators. DUH.]

    *

    Most if not all the holes - aside from those revealed through a laxity
    in patching Apache (no pun intended) - are most likely due to user
    ignorance or nonchalance.

    Apple boxes can be opened wide: it's possible to enable ordinary file
    sharing and even Windows file sharing (!) and it's generally not a
    good idea unless you really know what you're doing and only leave it
    enabled for as long as you need it.

    Whenever you open a box connected to the Internet - especially from a
    static IP - you're also opening it for the rest of the world. Add a
    trivial password to the mix and you have burnt toast.

    It's not possible to compromise an OS X or Unix system in the
    traditional way the Windows boxes get hit: none of them have the leaky
    sieve of the Internet Explorer rendering engine. But anyone, repeat
    'anyone', stupid enough to let the intruders gain access will end up
    with - the intruders gaining access!

    Use of remote root login, especially to boxes connected to the
    Internet, has to be one of the absolute dumbest ideas of all time.
    Normally an attacker has to guess a username and a password; if the
    root account is enabled, half the battle is over.

    Now hit the server with brute force and you will 0WN it...

    Remote users can always escalate to root once they're in; enabling
    root - default disabled by Apple out of the box and for obvious
    reasons - is just folly. Downright stupid.

    OS X comes with the BSD firewall. Turn this sucker on and nothing is
    visible. It's relatively easy to set the firewall up to only show
    one's presence on the ports to be used for communications. Even this
    should be turned off when not in use.

    And kitchen table users out there: are your root accounts enabled?
    They should not be. Root came from the factory disabled and you should
    have left it as such.

    And how about all the software you download? How many applications ask
    for your administrator password to install? And if they did, did you
    throw them in the Trash where they belong? Are you going to finally
    understand that no one but no one is to get this password except Apple
    themselves?

    On a final note: the Unicode exploit is platform-independent. This
    exploit relies on the fact that certain Unicode characters look
    EXACTLY like ordinary 7-bit ASCII - you access a site and it really
    looks like you're at the right site, but a single character is
    actually QUITE ANOTHER VALUE...

    Most browser manufacturers are writing (or have already completed)
    code to combat this exploit: it matters not what platform you are
    running on - get the patch now.

    Rounding up, let us quote from the gurus who found the OS X zombies:

    'OS X systems are secure, but their security issues cannot be ignored.
    Even though they've been good compared to their rowdy Windows cousins,
    they live in a dangerous world. Don't let hubris bite you!'

    Merci bien - until NeXT time...

    *

    All the best,

    J/R/S

    --------
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  • Next message: Tim O'Guin: "Re: [Full-disclosure] Hacked: Who Else Is Using Your Computer?"

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