Favicon bug can crash Chrome & Firefox browsers

Are you, at times, facing some strange Chrome or Firefox crashes these days? If yes, this might be due to the Favicon bug. Yes, a Favicon bug reportedly can crash your Chrome & Firefox browsers. Strange but true, the small little icon termed as Favicon can actually crash Chrome and Firefox browsers. The favicon bug was recently spotted by Andrea De Pasquale, security analyst and software developer.

firefox favicon bug

Andrea De Pasquale posted a tweet saying,

“Weird 64MB favicon.ico turning out to be a TAR backup of the whole WP site, downloaded by every browser passing by”

This creepy bug makes Chrome and Firefox download the huge favicon files to the point till they crash the browser. Weirdest is that thing that users are not at all aware of this download as it is all done in the background.

Favicon is a symbol image or an icon of a website which is displayed in the top left corner of the web browser. A Favicon is specifically 16X16 in size, but it seems that the bug has come from a favicon file which is wrongly sized.

What is this Favicon Bug

The browser downloads a huge 1GB favicon file without any visual indication and the browser becomes unresponsive and crashes eventually. The reason being that the system would run out of memory while trying to load in Chrome and crashes.

Running it

  • Install io.js (NodeJS works too)
  • Run: node exploit.js
  • Test your browser by visiting http://localhost:3000 (or if you have process.env.PORT set then that port)

Running it for Apple Touch Icon

  • Install io.js (NodeJS works too)
  • Run: node exploit-ios.js
  • Test on iOS by visiting http://ip-of-computer:3000 and tapping on the share icon (or if you have process.env.PORT set then that port)

While Chrome and Firefox are frequently facing this Favicon bug issue, Internet explorer seems to be okay says, says this report on Github, as there are no such issues reported by any of the IE users.

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Shiwangi Peswani is a qualified writer and a blogger, who loves to dabble with and write about computers and the Internet. While focusing on and writing on technology topics, her varied skills and experience enables her to write on any topics which may interest her.