4 ms·

"secure against what"? Do you mean the script in the webpage running in my browser tab might be attacked by some virus already running on my computer? Or do you

by skyde 5y ago

"secure against what"? Do you mean the script in the webpage running in my browser tab might be attacked by some virus already running on my computer? Or do you mean a virus running inside WebAssembly might attack my computer? If it's the first one, I dont think i really care.

sudosysgen 5y ago
neither, the program might just crash or be buggy. Maybe in some rare cases do malicious things to the programs running in the sandbox.
aaronharnly 5y ago
I think it’s more like: a script running in your browser tab, given some untrusted input (say, an image you import into an editing program) could be compromised by malicious input, such that the script runs malicious code and exfiltrates other data from the app (say, your email address or other private data you used on the page).
- azakai 5y ago
  That's a definite risk in general. But worth adding that Wasm by design lets you statically inspect all the things the Wasm can call. If the Wasm receives access to networking, or eval(), etc., then there is a real risk. However, often the Wasm imports and exports are extremely limited and easy to verify for safety.
chubot 5y ago
Section 5.1 gives a good example: an image sharing service that processes images using libpng. This has to be combined with a document.write() of HTML in C, which is realistic. Someone who controls the image data can perform an XSS, i.e. steal your credentials for the website, or your credit card info if that's stored server-side. That's not as valuable a target as controlling your computer, but it's not nothing, and can be chained. This is completely realistic as Figma is full blown image editor written in C++ compiled to WebAssembly :) https://www.figma.com/blog/webassembly-cut-figmas-load-time-by-3x/ https://www.figma.com/blog/webassembly-cut-figmas-load-time-...
- skyde 5y ago
  "Someone who controls the image data" to me that sound like something outside the sandbox manipulating the image data given to the sandbox. If this is the case it mean there is already a hacker or virus running outside the sandbox which mean I already have bigger problem to worry about :).
  - tasogare 5y ago
    No, it means a random user can upload a malicious image and hack the service.

by skyde 5y ago

sudosysgen 5y ago

neither, the program might just crash or be buggy. Maybe in some rare cases do malicious things to the programs running in the sandbox.

aaronharnly 5y ago

I think it’s more like: a script running in your browser tab, given some untrusted input (say, an image you import into an editing program) could be compromised by malicious input, such that the script runs malicious code and exfiltrates other data from the app (say, your email address or other private data you used on the page).

azakai 5y ago
That's a definite risk in general. But worth adding that Wasm by design lets you statically inspect all the things the Wasm can call. If the Wasm receives access to networking, or eval(), etc., then there is a real risk. However, often the Wasm imports and exports are extremely limited and easy to verify for safety.

chubot 5y ago

Section 5.1 gives a good example: an image sharing service that processes images using libpng. This has to be combined with a document.write() of HTML in C, which is realistic. Someone who controls the image data can perform an XSS, i.e. steal your credentials for the website, or your credit card info if that's stored server-side. That's not as valuable a target as controlling your computer, but it's not nothing, and can be chained. This is completely realistic as Figma is full blown image editor written in C++ compiled to WebAssembly :) https://www.figma.com/blog/webassembly-cut-figmas-load-time-by-3x/ https://www.figma.com/blog/webassembly-cut-figmas-load-time-...

skyde 5y ago
"Someone who controls the image data" to me that sound like something outside the sandbox manipulating the image data given to the sandbox. If this is the case it mean there is already a hacker or virus running outside the sandbox which mean I already have bigger problem to worry about :).
- tasogare 5y ago
  No, it means a random user can upload a malicious image and hack the service.