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copied!<p><em>Read this whole post before trying it out, there are choices to be made.</em></p> <hr> <h2>Solution using a binary wrapper (with suid bit)</h2> <p><strong>1)</strong> Create a script (preferrably <code>.sh</code>) that contains what you want to be ran as root.</p> <pre class="lang-none prettyprint-override"><code># cat > php_shell.sh <<CONTENT #!/bin/sh /sbin/service sshd restart CONTENT </code></pre> <p><strong>2)</strong> This file should be owned by root, and since it will later run with root permissions make sure that only root has permission to write to the file.</p> <pre class="lang-none prettyprint-override"><code># chown root php_shell.sh # chmod u=rwx,go=xr php_shell.sh </code></pre> <p><strong>3)</strong> To run the script as root no matter what user that executes it, we will need a binary wrapper. Create one that will execute our <code>php_shell.sh</code>.</p> <pre class="lang-none prettyprint-override"><code># cat > wrapper.c <<CONTENT #include <stdlib.h> #include <sys/types.h> #include <unistd.h> int main (int argc, char *argv[]) { setuid (0); /* WARNING: Only use an absolute path to the script to execute, * a malicious user might fool the binary and execute * arbitary commands if not. * */ system ("/bin/sh /path/to/php_shell.sh"); return 0; } CONTENT </code></pre> <p><strong>4)</strong> Compile and set proper permissions, including the suid bit (saying that it should run with root privileges):</p> <pre class="lang-none prettyprint-override"><code># gcc wrapper.c -o php_root # chown root php_root # chmod u=rwx,go=xr,+s php_root </code></pre> <p><code>php_root</code> will now run with root permissions, and execute the commands specified in <code>php_root.sh</code>.</p> <hr> <p>If you don't need to the option to easily change what commands that will be executed I'd recommend you to write the commands directly in <code>wrapper.c</code> under step <strong>4</strong>. Then you don't need to have a binary executing a external script executing the commands in question.</p> <p>In <code>wrapper.c</code>, use <code>system ("your shell command here");</code> to specify what commands you'd like to execute.</p>

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