[fw-wiz] The answer to the PIX encryption issue

From: Damir Rajnovic (gausat_private)
Date: Fri Jul 12 2002 - 05:38:03 PDT

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    This is in response to the mail sent by Michael Thumann and mao.
    The mail is available at
    http://archives.neohapsis.com/archives/vulnwatch/2002-q2/0121.html
    (Weak Cisco Pix Password Encryption Algorithm)
    
    When considering the published report one must take the following
    into the account:
    
    *) The password length and quality is very important.
    
       Using passwords with ten characters or more will make brute force
       attack much harder up to the point when they become computational
       infeasible using the present algorithms and general purpose computers.
       Using passwords which are not easy to guess, with a mixture of
       lower and upper case letters and numbers, will make off line dictionary
       attack much harder.
    
    *) This attack is effective only if an attacker can capture the
       configuration file.
    
       In order to prevent interception of the configuration files for the
       PIX particularly during transfer between devices, customers should
       review their policies and practices concerning storage and transfer
       of PIX configuration files. Critical points of review should include
       firewall management systems and backup procedure (including media and
       disposal).
    
    *) By default PIX will not accept interactive connections on any port
       except the console port.
    
       Even if an attacker possesses the password, an interactive
       administrative session must be established to the trusted/protected
       (or externally via IPSEC) interface of the PIX, in order to take
    advantage
       of this. Cisco configuration guides recommend explicit and careful
       configuration of permitted administrative hosts, and default
       configuration requires the administration hosts to be explicitly
       configured.
    
    *) Users are encouraged to use the local database that uses "salted"
       passwords. The example of a configuration is present here:
    
         username <user> password <secret password>
         aaa authentication enable console LOCAL
    
       Alternatively, users can consider using TACACS+ or Radius 
       for authentication.
    
       The practice of having a single, shared enable password should be
       discouraged in favor of creating a separate usernames with the
       appropriate privilege level. Additionally, a practice of sharing
       the same configuration file among multiple PIXes should be
       reconsidered. For the exact syntax of PIX command consult
    http://www.cisco.com/univercd/cc/td/doc/product/iaabu/pix/pix_sw/v_62/cmdref/
    index.htm
    
    
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    ==============
    Damir Rajnovic <psirtat_private>, PSIRT Incident Manager, Cisco Systems
    <http://www.cisco.com/go/psirt>      Telephone: +44 7715 546 033
    200 Longwater Avenue, Green Park, Reading, Berkshire RG2 6GB, GB
    ==============
    There is no insolvable problems. 
    The question is can you accept the solution? 
    
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