XML External Entities (XXE) Explained

#WebSecurity #XXE
A video on Exploiting XML parsers, specifically on XML External Entity attacks.
🔗 Links
John's channel : / rootofthenull
Stok's video on OOB XXE via file uploads : • A $7.500 BUG BOUNTY Bu...
Ippsec's Fulcrum walkthrough : • HackTheBox - Fulcrum
Nicolas Grégoire's works : www.agarri.fr/en/
Exploiting XXE with local DTD files : mohemiv.com/all/exploiting-xx...
SPONSORED BY INTIGRITI - intigriti.com
🎵 Track: Warriyo - Mortals (feat. Laura Brehm)
NCS link: • Warriyo - Mortals (fea...
#WebSecurity #XXE #CTF

[@iamwaseem99]

4:12 "S" in XML stands for "Security"....LOL

[@ari_archer]

that's the point hah

[@ShawSumma]

SGML?

[@cyberpro151]

are you a bug bounty hunter?

[@TryX10]

Even though most of the time I don't completely understand every bit, I really like your editing and presentation of these (for me) 'complex' topics! Keep it up! You're doing great man!

[@youssefighzane1668]

Well, well, well !! That's more than AMAAAAAAAAAAAZING !!! I was unable to understand XML and XXE as well until I watch your video. Thank you so much !! RECOMMENDED FOR ALL #BUG_BOUNTY_HUNTERS

[@InfiniteLogins]

I really appreciate your video editing techniques. Make the content easy to follow and engaging.

[@dxsp1d3r]

Why didnt i find this before Awesome stuff man Thank you I came to know about this channel from stoks tweets xD

[@Yaxqb]

The framework for explaining stuff is amazing. About every other video has a ncat -l 1337 command in it, and it has become a standard practice for me in my own work to use that command. The pwnfunction toolbox feels very versatile👍 Really really nice!

[@reema6306]

I've spent a week learning XML and XXE, and your video just summarized 80% of what I learned. Great job!

[@fmattia99]

John's voice is equal to IppSec's voice, this blew my mind :D

[@abdallahdamnat382]

Fel

[@markgentry8675]

hahahaha not just me that got confused for a second

[@Sercan_Yilmaz]

He is ippsec ;) John Hammond

[@thedude8503]

I love this channel, the people in it and the people subscribed to it. Thank you for making it simple

[@aniceguy2577]

This is pure gold. Thx for the great content

[@seewhatseeabc]

Wow love this style. By the way thanks for the super clear explanation. Especially with the examples, super good clear cut examples.

[@domss1174]

Loving your channel man, keep up the good work!

[@zanidd]

I really like the style of your vids! Keep em coming

[@abdelrhmanali2955]

Your explanation is really AWESOME bro

[@petervsjim]

THanks for the awesome video and slides! Very clear and knowledgeable

[@P4cm4n0x]

Best explanation ever. Very very to the point. Thank you :)

[@sakyb7]

xxe is just a beginning this line with the background... goosebumps

[@rhenaldodelfinugraha9694]

Awesome explanation. It's easy to understand, Thankyou. Please make another cool videos

[@TheZethera]

I just have to say your opening and music are perfect 👌

[@DeltaEchoVictor]

It's name is mortals

[@iDontProgramInCpp]

3:56 diReRectly

[@synthdog2819]

17:06 willbewillbe

[@HyderAli-hl8mw]

Very informational for beginners. Thank you so much

[@mikekittelberger7947]

omg, thank you. This video is so godd :)

[@venkaraj]

Such an insightful video. Thanks a ton

[@FriedMonkey362]

I have litterly never heard about this before, this is so cool, i almost tought it was an April fool's video for a second

[@joshaprior3699]

first GREAT CHANNEL

[@tapank415]

@// Anuj ó_ó

[@pwndumb2903]

Great Video. Thx for share your knowledge.

[@rahulnair1923]

Loved the explanation !!!!!!!!!!🤩

[@janithmalinga5765]

Superb explanation

[@AkashRaj-ui1pj]

Your videos are a aaaaaaaaaamaaaaaazinggggg

[@Hope-kf1nl]

You're a hero! Thanks my man.

[@hydr0nium_]

Never heared of that attack before the video. Soo wow amazing. If you think about it its quite simple actually. Btw is there a way of secure it easiely?

[@carloszavaleta]

Awesome content!

[@anonymouseye4892]

Nice explanation 🔥

[@shrirangdiwakar]

Great Explanation !

[@medjassertoubib4467]

great video . we look forward to new videos

[@kinjalsangale1225]

Please make more videos on different vulnerabilities... explainions are 👌

[@devsingh6041]

this video is sufficient to understand XXE. Thanks Pwn You Func well ;-)

[@CosmoCopulates1]

Dude, your videos are great! What do you use to create the animations?

[@PwnFunction]

Adobe animate boi.

[@SatsJava]

You deserved million subscriber Keep make more videos mate

[@PwnFunction]

Well that's a longgggggggggg way. Don't think I could ever hit such crazy numbers, If I hit 10k then I feel like I've accomplished something :) but thanks.

[@0xExploitXpErtz]

@@PwnFunction u will surely achieve it IA

[@faizannehal1]

This is the best video on XXE

[@tanishqsachdev8388]

Amazing video.

[@emmanuelafolabi6847]

Great videom your videos has been educative, can you make a video on based XSS?

[@PwnFunction]

Next one!

[@eshaan7_]

What theme for VScode and terminal are u using? BTW Great video, thanks!

[@PwnFunction]

Monokai Pro Terminus - eugeny.github.io/terminus/

[@ashleypursell9702]

great video thanks so much

[@muhammadadel9537]

Super AWESOME!!

[@huntit4578]

What software do u use to make these slideshow or animation (Whatever) to explain these attacks in such a interesting way?

[@tapank415]

:) Amazing!

[@heycherry100]

very nice video.

[@patrickslomian7423]

Love your channel Bro !! So I ran into a failure with Dvwa in the section "file upload",I"ve tried to upload an file with the payload. It seems to me that the server (using docker) wont phrase an xml file, can that be true ? Im getting this error :" This XML file does not appear to have any style information associated with it. The document tree is shown below. " Or should I converte that to an html file ?

[@nuridincersaygili]

This is pure gold..

[@neadlead2621]

thanks bro , I've one question at 18:05 why we need %start and %end why not changing them directely to the value

[@Manabender]

So how does one defend against this? Say I was running the server you were attacking and *didn't* want you reading /etc/passwd, but still wanted to retain as much (safe) functionality of the XML parser as possible. What would I do?

[@aidenrhama9147]

what software did you use to make this content ?

[@prudhvidanyamraju8017]

On a certain java server I’m able to retrieve the data of /sys/power/image_size (basically an number) using OOB xxe but I’m unable to retrieve contents of etc/passwd ; any thoughts?

[@BALAKRISHNAN-pf1ol]

Can you attatch a link to the xml parser you used in the video

[@r4nd0m25]

god level videos

[@Pcpiee]

What terminal do you use for the examples? it looks very nice. guessing its cygwin based by the looks of it

[@PwnFunction]

Terminus - eugeny.github.io/terminus/

[@jasonmikinskiwallet4308]

I love the Intro

[@erdosamangeldin3105]

& sign showing error while referencing an entity. I tried in ascii or hex too, it is not working. Is there any other ways to reference it?

[@tekken-pakistan2718]

damn boi, that outro tho!

[@helloguy1179]

What should I do if I have to configure a http request to get a file's information, but its content contains special character? We cannot use CDATA in a URL, right?

[@SatriaAdyPradana]

do you have git repo which collect the scripts and XML files used here?

[@itizazadil9369]

Thanks for the Vedio

[@user-tz5rd3rt2s]

Nice Stuff

[@giospadaccini119]

In Italy xml is use to send invoices to the IRS, and after few day it sand that to you client .... So this video reassuring me..

[@tekken-pakistan2718]

nice as always! Can you please share your terminal's configuration/name etc.? is it zsh with custom config? Thanks mch!

[@PwnFunction]

Terminal : eugeny.github.io/terminus/ Yes i'm using ohmyzsh (default theme : robbyrussell)

[@aleksandar5323]

How can I disable XML parser resources referencing on say an Apache Server? I don't want XML to be making any requests at all, either internal or God forbid accessing a 3rd party URL! I just want hard-coded data from it...

[@user-xb9zg3fv9j]

hey hey hey sir please tell this theme of zsh. I tried searching all of them but i didn't find anyone like this please do tell.

[@yeasirarafat4261]

awesome

[@Wikkido5000]

do you have a similar video for JSON?

[@Sparkette]

Is it okay to use a '

[@generalinformation3194]

hello can i get the xmlsax_parser tool you use it in the video plz

[@overgrowncarrot1]

I like how John hammond says I have a small youtube channel lol

[@xf4229]

I am having issue accessing id_rsa in .ssh file. Is there any way to bypass it? The current issue is I/O warning: fail to load external entity.

[@asjidkalam]

is stok's video on OOB XXE private?

[@aymanrbati531]

why cant u declare the "send" entity directly in the external DTD ? why put it inside 'wrapper' ?

[@anatolyrapoport2216]

Nice tutorial!

[@vijaykumar-hc6jz]

Why DTD is so called ? It could have also been called Entity Defintition or something like that ? Any answer to this is appeciated.

[@alexanderwu]

So... How do you defend against it?

[@annomy1493]

voice seems to be known. Is it john harmmond ???

[@stefaunholland6642]

The way you say "parameter" makes me think of a parking meter with a parachute falling out the sky - an American

[@patricksteinmuller8084]

Tbh. I wonder why anyone would use DTD anyhow? The reason I am so fond of XML is the existence of XSD and XSLTs. A well defined XML is both human readible and machine readible. Can be validated against an XSD, can be transformed against an XSLT and have XSD, XSLT and both XML input and XML ouput validated against respective XSDs. This is not something that we have for json or yaml. I was to lazy to look ... I somehow suspect that we have similar attack vectors in the X* Suite.

[@zanidd]

I'd like to do a similar style collab, if you're into it send me an email!

[@laurinneff4304]

It would've been great if you had included a segment on how to protect against these attacks

[@Morgan_iv]

Just don't use XML

[@coastaldemigod]

my engineering professor taught the first 10 mins. of this video in 1 month

[@d86123]

那麼...問題是，如何防止XXE注入攻擊呢?

[@ca7986]

♥️

[@acunsumageka3949]

tools for xml parser ?

[@tuttifrutti4184]

holy shit this is so hard to understand, but I suppose it's supposed to be this way unless you actually practise using XML for quite some time

[@IBMboy]

9:47 My name is jeff. Nice meme

[@puravida012]

this is soo old, HTB show something like this almost a year ago

[@PwnFunction]

Yeah it's very old, you can even find stuff about it, way back in 2002. www.securityfocus.com/archive/1/297714/2002-10-27/2002-11-02/0

[@eduardoandrescastilloperer4810]

OMG why was that even encoded into the standard!!!

[@lexibigcheese]

so that's why there's a doctype html. that's what it's for!

[@JD-mz1rl]

I don't get it. Unless the web server is running with root permissions, what useful files are you going to get out of it?

[@Aidiakapi]

It's not just for web servers, it can compromise clients too. Getting someone to open a document and extract information. As for what useful files, plenty of web servers will have access to many useful files. Configuration files, uploaded artifacts, etc.

[@ctfs09]

there is something you need to explore more! You don't have to be root, its not about editing , it is just exfiltrating and you don't have to be root! Try cat /etc/passwd without being root and even you can see that.

[@hellb0y794]

your sound like @liveoverflow, are you his brother? 😆

[@uplink-on-yt]

My reaction (comment, not video): eyes open wide, mouth covered with hand, deep breath - AKA "Surprised Pikachu". This is possibly one ofvthe most evil things I've ever seen (yeah... I'm pretty innocent)

[@gcm4312]

can you link that python xml parser?

[@PwnFunction]

I don't have the code with me, but I hope this can be helpful - docs.python.org/3/library/xml.sax.reader.html

[@mylyf6684]

Hai bro will you please share that python script for parsing XML. please...

[@PwnFunction]

I don't have the code, but it was a simple sax xml parser written in python - docs.python.org/3/library/xml.sax.reader.html

[@kallikantzaros]

from lxml import etree parser = etree.XMLParser(load_dtd=True, no_network=False) tree = etree.parse("main_attack.xml", parser=parser) etree.dump(tree.getroot())

[@arenddejong6609]

LiveOverflow JohnHammond 2.0

[@adityashrest6334]

what is inside xxe praser python

[@PwnFunction]

I don't have the code, but I think it was just reading the XML file and spitting out the output(after processing). And I used sax - docs.python.org/3/library/xml.sax.reader.html