Part of djb series
        In hpgl-input.c, ParseCommand() reads any number of bytes into
        a 262144-byte buf[] array.
        http://tigger.uic.edu/~jlongs2/holes/cups.txt

        First, lppasswd blithely ignores write errors in
        fputs(line,outfile) at lines 311 and 315 of lppasswd.c, and in
        fprintf(...) at line 346. An attacker who fills up the disk at
        the right moment can arrange for /usr/local/etc/cups/passwd to
        be truncated.

        Second, if lppasswd bumps into a file-size resource limit
        while writing passwd.new, it leaves passwd.new in place,
        disabling all subsequent invocations of lppasswd. Any local
        user can thus disable lppasswd by running the attached program
        63.c.

        Third, line 306 of lppasswd.c prints an error message to
        stderr but does not exit. This is not a problem on systems
        that ensure that file descriptors 0, 1, and 2 are open for
        setuid programs, but it is a problem on other systems;
        lppasswd does not check that passwd.new is different from
        stderr, so it ends up writing a user-controlled error message
        to passwd if the user closes file descriptor 2.

        http://tigger.uic.edu/~jlongs2/holes/cups2.txt