| 1 | SECURITY NOTE
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| 2 |
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| 3 | Al Woodhull <awoodhull@hampshire.edu> 2003-07-05
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| 4 |
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| 5 | Running a web server is fun, but it's also not without risks. If, like
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| 6 | many Minix users, you are a guest on someone else's network, you need
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| 7 | to be very careful to operate your server in ways that will not put
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| 8 | your system at risk or interfere with others on the net. Here are some
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| 9 | points to consider:
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| 10 |
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| 11 | - Be sure to touch /usr/adm/httpd.log (or whatever you specify as the log
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| 12 | file in httpd.conf) before you start your web server for the first time
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| 13 | -- nothing will be logged if the log file does not exist. Then look at
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| 14 | your log file frequently and be alert for any unusual activity.
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| 15 |
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| 16 | - You may also want to be sure that tcpd is configured to operate in
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| 17 | PARANOID mode. That will enable logging of connection attempts and
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| 18 | allow you to use the serv.access (5) file to limit the kinds of
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| 19 | connections that your system allows.
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| 20 |
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| 21 | - If you enable proxy webserving, be very careful, it can be used by
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| 22 | people you don't know to visit sites that don't welcome visitors whose
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| 23 | identity is hidden. This may cause your network host and ultimately you
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| 24 | some unpleasantness.
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| 25 |
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| 26 | - The Minix httpd can also support CGI applications. These are also
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| 27 | dangerous -- a CGI application allows someone else to execute a program
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| 28 | on your computer. Make sure anything you allow this way cannot be
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| 29 | abused. Many security violations are due to effects of input that was not
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| 30 | expected by the original author of a program.
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| 31 |
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| 32 | - It's an understatement to say that Minix is not a well-known
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| 33 | operating system. There are not many Minix systems operating as
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| 34 | servers on the internet. A consequence of this is that there few, if
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| 35 | any, people engaged in finding ways to attack weaknesses in Minix. But
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| 36 | the idea of "security through obscurity" is deprecated by serious
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| 37 | computer security experts. Any operating system or program of any
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| 38 | degree of complexity is likely to have bugs or features that can be
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| 39 | exploited in ways the original programmers did not foresee. You can't
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| 40 | count on the "good guys" being the first ones to discover a risk.
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| 41 | There are two things you should be sure to do if you are running a
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| 42 | network server of any kind:
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| 43 |
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| 44 | (1) be alert for new versions of the program that may fix bugs
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| 45 | discovered by other users, and
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| 46 |
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| 47 | (2) be sure to report to the program author or maintainer anything you
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| 48 | observe that looks like a bug or a way the program can be misused.
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