53 lines
2.5 KiB
Text
53 lines
2.5 KiB
Text
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SECURITY NOTE
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Al Woodhull <asw@woodhull.com> updated 2006-06-01
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Running a web server is fun, but it's also not without risks. If, like
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many Minix users, you are a guest on someone else's network, you need
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to be very careful to operate your server in ways that will not put
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your system at risk or interfere with others on the net. Here are some
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points to consider:
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- Be sure to touch /usr/adm/httpd.log (or whatever you specify as the log
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file in httpd.conf) before you start your web server for the first time
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-- nothing will be logged if the log file does not exist. Then look at
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your log file frequently and be alert for any unusual activity.
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- You may also want to be sure that you have provided a /etc/serv.access
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file. This file can be used to limit access only to permitted nodes or
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networks, or to deny access to specified nodes or networks (see the
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serv.access (5) man page). Also, even if your /etc/serv.access file is
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empty, if it is present tcpd will exec its paranoid twin tcpdp, which
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will refuse service if the connecting IP address cannot be associated
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with a name.
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- If you enable proxy webserving, be very careful, it can be used by
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people you don't know to visit sites that don't welcome visitors whose
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identity is hidden. This may cause your network host and ultimately you
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some unpleasantness.
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- The Minix httpd can also support CGI applications. These are also
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dangerous -- a CGI application allows someone else to execute a program
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on your computer. Make sure anything you allow this way cannot be
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abused. Many security violations are due to effects of input that was not
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expected by the original author of a program.
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- It's an understatement to say that Minix is not a well-known
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operating system. There are not many Minix systems operating as
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servers on the internet. A consequence of this is that there few, if
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any, people engaged in finding ways to attack weaknesses in Minix. But
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the idea of "security through obscurity" is deprecated by serious
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computer security experts. Any operating system or program of any
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degree of complexity is likely to have bugs or features that can be
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exploited in ways the original programmers did not foresee. You can't
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count on the "good guys" being the first ones to discover a risk.
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There are two things you should be sure to do if you are running a
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network server of any kind:
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(1) be alert for new versions of the program that may fix bugs
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discovered by other users, and
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(2) be sure to report to the program author or maintainer anything you
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observe that looks like a bug or a way the program can be misused.
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