注入漏洞代码和分析 先上代码 ? php function customError( $errno , $errstr , $errfile , $errline ) { echo "bError number:/b [ $errno ],error on line $errline in $errfile br /" ; die (); } set_error_handler ("customError", E_ERROR ); $getfilt
注入漏洞代码和分析
先上代码


<?<span>php
</span><span>function</span> customError(<span>$errno</span>, <span>$errstr</span>, <span>$errfile</span>, <span>$errline</span><span>)
{
</span><span>echo</span> "<b>Error number:</b> [<span>$errno</span>],error on line <span>$errline</span> in <span>$errfile</span><br />"<span>;
</span><span>die</span><span>();
}
</span><span>set_error_handler</span>("customError",<span>E_ERROR</span><span>);
</span><span>$getfilter</span>="'|(and|or)\b.+?(>|<|=|in|like)|\/\*.+?\*\/|<\s*script\b|\bEXEC\b|UNION.+?SELECT|UPDATE.+?SET|INSERT\s+INTO.+?VALUES|(SELECT|DELETE).+?FROM|(CREATE|ALTER|DROP|TRUNCATE)\s+(TABLE|DATABASE)"<span>;
</span><span>$postfilter</span>="\b(and|or)\b.{1,6}?(=|>|<|\bin\b|\blike\b)|\/\*.+?\*\/|<\s*script\b|\bEXEC\b|UNION.+?SELECT|UPDATE.+?SET|INSERT\s+INTO.+?VALUES|(SELECT|DELETE).+?FROM|(CREATE|ALTER|DROP|TRUNCATE)\s+(TABLE|DATABASE)"<span>;
</span><span>$cookiefilter</span>="\b(and|or)\b.{1,6}?(=|>|<|\bin\b|\blike\b)|\/\*.+?\*\/|<\s*script\b|\bEXEC\b|UNION.+?SELECT|UPDATE.+?SET|INSERT\s+INTO.+?VALUES|(SELECT|DELETE).+?FROM|(CREATE|ALTER|DROP|TRUNCATE)\s+(TABLE|DATABASE)"<span>;
</span><span>function</span> StopAttack(<span>$StrFiltKey</span>,<span>$StrFiltValue</span>,<span>$ArrFiltReq</span><span>)
{
</span><span>if</span>(<span>is_array</span>(<span>$StrFiltValue</span><span>))
{
</span><span>$StrFiltValue</span>=<span>implode</span>(<span>$StrFiltValue</span><span>);
}
</span><span>if</span> (<span>preg_match</span>("/".<span>$ArrFiltReq</span>."/is",<span>$StrFiltValue</span>)==1&&!<span>isset</span>(<span>$_REQUEST</span>['securityToken'<span>]))
{
slog(</span>"<br><br>操作IP: ".<span>$_SERVER</span>["REMOTE_ADDR"]."<br>操作时间: ".<span>strftime</span>("%Y-%m-%d %H:%M:%S")."<br>操作页面:".<span>$_SERVER</span>["PHP_SELF"]."<br>提交方式: ".<span>$_SERVER</span>["REQUEST_METHOD"]."<br>提交参数: ".<span>$StrFiltKey</span>."<br>提交数据: ".<span>$StrFiltValue</span><span>);
</span><span>print</span> "result notice:Illegal operation!"<span>;
</span><span>exit</span><span>();
}
}
</span><span>foreach</span>(<span>$_GET</span> <span>as</span> <span>$key</span>=><span>$value</span><span>)
{
StopAttack(</span><span>$key</span>,<span>$value</span>,<span>$getfilter</span><span>);
}
</span><span>foreach</span>(<span>$_POST</span> <span>as</span> <span>$key</span>=><span>$value</span><span>)
{
StopAttack(</span><span>$key</span>,<span>$value</span>,<span>$postfilter</span><span>);
}
</span><span>foreach</span>(<span>$_COOKIE</span> <span>as</span> <span>$key</span>=><span>$value</span><span>)
{
StopAttack(</span><span>$key</span>,<span>$value</span>,<span>$cookiefilter</span><span>);
}
</span><span>function</span> slog(<span>$logs</span><span>)
{
</span><span>$toppath</span>="log.htm"<span>;
</span><span>$Ts</span>=<span>fopen</span>(<span>$toppath</span>,"a+"<span>);
</span><span>fputs</span>(<span>$Ts</span>,<span>$logs</span>."
"<span>);
</span><span>fclose</span>(<span>$Ts</span><span>);
}
</span>?>
分析
如果使用这个函数的话,这个函数会绕开PHP的标准出错处理,所以说得自己定义报错处理程序(die())。
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其次,如果代码执行前就发生了错误,那个时候用户自定义的程序还没有执行,所以就不会用到用户自己写的报错处理程序。
那么,PHP里有一套错误处理机制,可以使用set_error_handler()接管PHP错误处理,也可以使用trigger_error()函数主动抛出一个错误。
set_error_handler()函数设置用户自定义的错误处理函数。函数用于创建运行期间的用户自己的错误处理方法。它需要先创建一个错误处理函数,然后设置错误级别。
关于的用法:
<span> 1</span> <span>function</span> customError(<span>$errno</span>, <span>$errstr</span>, <span>$errfile</span>, <span>$errline</span><span>)
</span><span> 2</span>
<span> 3</span> <span>{
</span><span> 4</span>
<span> 5</span> <span>echo</span> "<b>错误代码:</b> [${errno}] ${errstr}\r\n"<span>;
</span><span> 6</span>
<span> 7</span> <span>echo</span> " 错误所在的代码行: {<span>$errline</span>} 文件{<span>$errfile</span>}\r\n"<span>;
</span><span> 8</span>
<span> 9 </span> <span>echo</span> " PHP版本 ",<span>PHP_VERSION</span>, "(" , <span>PHP_OS</span>, ")\r\n"<span>;
</span><span>10</span>
<span>11</span> <span>//</span><span> die();</span>
<span>12</span>
<span>13</span> <span>}
</span><span>14</span>
<span>15</span> <span>set_error_handler</span>("customError",<span>E_ALL</span>| <span>E_STRICT</span><span>);</span><span><br /></span>在这个函数里,可以做任何要做的事情,包括对错误的详情进行格式化输出,记入log文件。
<span>1</span> <span>function</span> slog(<span>$logs</span><span>)
</span><span>2</span> <span>{
</span><span>3</span> <span>$toppath</span>="log.htm"<span>;
</span><span>4</span> <span>$Ts</span>=<span>fopen</span>(<span>$toppath</span>,"a+"<span>);
</span><span>5</span> <span>fputs</span>(<span>$Ts</span>,<span>$logs</span>."
"<span>);
</span><span>6</span> <span>fclose</span>(<span>$Ts</span><span>);
</span><span>7</span> }
自定义的错误处理函数一定要有这四个输入变量$errno、$errstr、$errfile、$errline。
errno是一组常量,代表错误的等级,同时也有一组整数和其对应,但一般使用其字符串值表示,这样语义更好一点。比如E_WARNING,其二进制掩码为4,表示警告信息。
接下来,就是将这个函数作为回调参数传递给set_error_handler。这样就能接管PHP原生的错误处理函数了。要注意的是,这种托管方式并不能托管所有种类的错误,如E_ERROR、E_PARSE、E_CORE_ERROR、E_CORE_WARNING、E_COMPILE_ERROR、E_COMPILE_WARNING,以及E_STRICT中的部分。这些错误会以最原始的方式显示,或者不显示。
StopAttack()函数是将传递过来的POST、GET、COOKIE进行正则表达式和调用slog()写入log文件。
几种常见攻击的正则表达式
<span>1</span> <span>$Exec_Commond</span> = "( \s|\S)*(exec(\s|\+)+(s|x)p\w+)(\s|\S)*"<span>;
</span><span>2</span> <span>$Simple_XSS</span> = "( \s|\S)*((%3C)|<)((%2F)|/)*[a-z0-9%]+((%3E)|>)(\s|\S)*"<span>;
</span><span>3</span> <span>$Eval_XSS</span> = "( \s|\S)*((%65)|e)(\s)*((%76)|v)(\s)*((%61)|a)(\s)*((%6C)|l)(\s|\S)*"<span>;
</span><span>4</span> <span>$Image_XSS</span> = "( \s|\S)*((%3C)|<)((%69)|i|I|(%49))((%6D)|m|M|(%4D))((%67)|g|G|(%47))[^\n]+((%3E)|>)(\s|\S)*"<span> ;
</span><span>5</span> <span>$Script_XSS</span> = "( \s|\S)*((%73)|s)(\s)*((%63)|c)(\s)*((%72)|r)(\s)*((%69)|i)(\s)*((%70)|p)(\s)*((%74)|t)(\s|\S)*"<span>;
</span><span>6</span> <span>$SQL_Injection</span> = "( \s|\S)*((%27)|(')|(%3D)|(=)|(/)|(%2F)|(")|((%22)|(-|%2D){2})|(%23)|(%3B)|(;))+(\s|\S)*";
总结
PHP遇到错误时,就会给出出错脚本的位置、行数和原因,有很多人说,这并没有什么大不了。但泄露了实际路径的后果是不堪设想的,对于某些入侵者,这个信息可是非常重要,而事实上现在有很多的服务器都存在这个问题。 有些网管干脆把PHP配置文件中的 display_errors 设置为 Off 来解决,但本人认为这个方法过于消极。有些时候,我们的确需要PHP返回错误的信息以便调试。而且在出错时也可能需要给用户一个交待,甚至导航到另一页面。但是有了set_error_handler()之后,这些矛盾也都可以解决掉了。
但是发现很少用这个函数。
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