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TongdaOA v11.6 print.php 任意文件删除&RCE

# TongdaOA v11.6 print.php 任意文件删除&RCE ## 漏洞描述通过任意文件漏洞删除上传点包含的身份验证文件，从而造成未授权访问实现任意文件上传 ## 漏洞影响 TongdaOA v11.6...

TongdaOA v11.6 print.php 任意文件删除&amp;RCE
=======================================

漏洞描述
----

通过任意文件漏洞删除上传点包含的身份验证文件，从而造成未授权访问实现任意文件上传

漏洞影响
----

TongdaOA v11.6

环境搭建
----

TongdaOA v11.6下载链接:<https://cdndown.tongda2000.com/oa/2019/TDOA11.6.exe>

漏洞复现
----

使用解密工具 SeayDzend(zend解密工具) 对TongdaOA的加密代码进行解密

解密完成后查看 `webroot\general\data_center\utils\upload.php` 文件

```php
<?php

include_once "inc/auth.inc.php";
include_once "./utils.func.php";
$HTML_PAGE_TITLE = _("上传文件");
include_once "inc/header.inc.php";
$error = "";
$msg = "";

if ($action == "upload") {
    if ($filetype == "xls") {
        $uploaddir = MYOA_ATTACH_PATH . "/data_center/templates/";

if (!is_dir(MYOA_ATTACH_PATH . "/data_center/templates")) {
            if (!is_dir(MYOA_ATTACH_PATH . "/data_center")) {
                mkdir(MYOA_ATTACH_PATH . "/data_center");
            }

mkdir(MYOA_ATTACH_PATH . "/data_center/templates");
        }

if (move_uploaded_file($_FILES["FILE1"]["tmp_name"], $uploaddir . $_FILES["FILE1"]["name"])) {
        }
    }
    else if ($filetype == "img") {
        $uploaddir = MYOA_ATTACH_PATH . "/data_center/images/";

if (!is_dir(MYOA_ATTACH_PATH . "/data_center/images")) {
            if (!is_dir(MYOA_ATTACH_PATH . "/data_center")) {
                mkdir(MYOA_ATTACH_PATH . "/data_center");
            }

mkdir(MYOA_ATTACH_PATH . "/data_center/images");
        }

$s_n = $_FILES["FILE1"]["name"];

if ($s_n[0] != "{") {
            $p = strrpos($s_n, ".");
            $s_n = CreateId() . substr($s_n, $p);
        }

if (move_uploaded_file($_FILES["FILE1"]["tmp_name"], $uploaddir . $s_n)) {
        }
    }
    else {
        $uploaddir = MYOA_ATTACH_PATH . "/data_center/attachment/";

if (!is_dir(MYOA_ATTACH_PATH . "/data_center/attachment")) {
            if (!is_dir(MYOA_ATTACH_PATH . "/data_center")) {
                mkdir(MYOA_ATTACH_PATH . "/data_center");
            }

mkdir(MYOA_ATTACH_PATH . "/data_center/attachment");
        }

if (isset($from_rep)) {
            if (($from_rep != "") && ($from_rep[0] == "{")) {
                $repkid = GetRepKIDBySendId($from_rep);

if ($repkid != $to_rep) {
                    if (file_exists($uploaddir . "/" . $repkid . "_" . $filename)) {
                        copy($uploaddir . "/" . $repkid . "_" . $filename, $uploaddir . "/" . $to_rep . "_" . $filename);
                    }
                }
            }
            else {
                $arr = explode(",", $from_rep);

for ($i = 0; $i < count($arr); $i++) {
                    $p = strpos($arr[$i], ".");
                    $repno = substr($arr[$i], 0, $p);
                    $repkid = GetRepKIDByNo($repno);

if ($repkid != $to_rep) {
                        if (file_exists($uploaddir . "/" . $repkid . "_" . $filename)) {
                            copy($uploaddir . "/" . $repkid . "_" . $filename, $uploaddir . "/" . $to_rep . "_" . $filename);
                            break;
                        }
                    }
                }
            }
        }
        else {
            $s_n = $_FILES["FILE1"]["name"];

if ($s_n[0] != "{") {
                $s_n = $repkid . "_" . $s_n;
            }

if (move_uploaded_file($_FILES["FILE1"]["tmp_name"], $uploaddir . $s_n)) {
            }
        }
    }

@unlink($_FILES["FILE1"]);
}
else if ($action == "unupload") {
    if ($filetype == "xls") {
        $uploaddir = MYOA_ATTACH_PATH . "data_center/attachment/" . trim($filename) . ".xls";

if (is_file($uploaddir)) {
            unlink($uploaddir);
        }
    }
    else if ($filetype == "img") {
        $uploaddir = MYOA_ATTACH_PATH . "data_center/images/" . trim($filename);

if (is_file($uploaddir)) {
            unlink($uploaddir);
        }
    }
    else if ($filetype == "attach") {
        $uploaddir = MYOA_ATTACH_PATH . "data_center/attachment/" . trim($filename);

if (is_file($uploaddir)) {
            unlink($uploaddir);
        }
    }
}

echo "{";
echo "new_name:'$s_n',\n";
echo "error: '" . $error . "',\n";
echo "msg: '" . $msg . "'\n";
echo "}";
echo "<body>\r\n</body>\r\n</html>";

?>
```

在第一行包含了文件 `auth.inc.php`

```php
include_once "inc/auth.inc.php";
```

![img](https://shs3.b.qianxin.com/butian_public/f539332a538186a04b4c59a08b8b480accbb17fe04573.jpg)

可以看到这个文件用于检验是否登录，未登录的情况无法利用这个漏洞

查看 `\webroot\module\appbuilder\assets\print.php`文件

![img](https://shs3.b.qianxin.com/butian_public/f417637d0606d4a8a5bfb6e24a8b5b73f1664b96d802e.jpg)

```php
<?php

$s_tmp = __DIR__ . "/../../../../logs/appbuilder/logs";
$s_tmp .= "/" . $_GET["guid"];

if (file_exists($s_tmp)) {
    $arr_data = unserialize(file_get_contents($s_tmp));
    unlink($s_tmp);
    $s_user = $arr_data["user"];
}
else {
    echo "未知参数";
    exit();
}
```

这里可以看到 页面获取 guid参数的值  
使用`file_exists函数`判断文件是否存在 并未进行校验 就执行unlink删除文件

可以本地在 `\webroot\inc` 目录创建 1.txt 文件

然后访问

```php
/module/appbuilder/assets/print.php?guid=../../../webroot/inc/1.txt
```

就会删除这个 1.txt 文件，也代表可以删除 `auth.inc.php` 登录检验文件

回到 upload.php 文件进行代码审计

![img](https://shs3.b.qianxin.com/butian_public/f5493165ec6cc4afab0ae716d66d3d9b11a2232d94994.jpg)

判断变量 `$action` 是否为 upload，再判断文件类型，如果不为 xls 和 img 则进入else分支

```php
else {
        $uploaddir = MYOA_ATTACH_PATH . "/data_center/attachment/";

if (!is_dir(MYOA_ATTACH_PATH . "/data_center/attachment")) {
            if (!is_dir(MYOA_ATTACH_PATH . "/data_center")) {
                mkdir(MYOA_ATTACH_PATH . "/data_center");
            }

mkdir(MYOA_ATTACH_PATH . "/data_center/attachment");
        }

if (isset($from_rep)) {
            if (($from_rep != "") && ($from_rep[0] == "{")) {
                $repkid = GetRepKIDBySendId($from_rep);

for ($i = 0; $i < count($arr); $i++) {
                    $p = strpos($arr[$i], ".");
                    $repno = substr($arr[$i], 0, $p);
                    $repkid = GetRepKIDByNo($repno);

if ($repkid != $to_rep) {
                        if (file_exists($uploaddir . "/" . $repkid . "_" . $filename)) {
                            copy($uploaddir . "/" . $repkid . "_" . $filename, $uploaddir . "/" . $to_rep . "_" . $filename);
                            break;
                        }
                    }
                }
            }
        }
        else {
            $s_n = $_FILES["FILE1"]["name"];

if ($s_n[0] != "{") {
                $s_n = $repkid . "_" . $s_n;
            }

if (move_uploaded_file($_FILES["FILE1"]["tmp_name"], $uploaddir . $s_n)) {
            }
        }
    }

@unlink($_FILES["FILE1"]);
}
```

在这段代码中，如果不存在 `$from_rep` 变量则会跳到如下代码

```php
else {
            $s_n = $_FILES["FILE1"]["name"];

if ($s_n[0] != "{") {
                $s_n = $repkid . "_" . $s_n;
            }

if (move_uploaded_file($_FILES["FILE1"]["tmp_name"], $uploaddir . $s_n)) {
            }
        }
```

这里直接将 `$repkid` 变量进行拼接,也就是说可以通过目录穿越来上传恶意文件到指定目录

发表于 2024-07-12 18:44:25
阅读 ( 928 )
分类：OA产品

TongdaOA v11.6 print.php 任意文件删除&RCE

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