Summary

Google Chrome has two places (credits pages and default sites) where HTTP links are used instead of HTTPS, which can lead to MITM attacks on a hostile network. The vendor doesn’t consider these to be security bugs and they remain unfixed.

Bug Details – Default Sites

On startup, Chrome for Android displays a search bat and 8 icons of commonly accessed sites. If the browser has not yet collected any history data, those icons default to the ones provided by a Google-hosted service (“https://www.gstatic.com/chrome/ntp/suggested_sites_DEFAULT_5.json“). These default sites are country specific. However, not all of these links use HTTPS – some use HTTP. As the result if a user is on a hostile network and taps any of these sites, the connection can be intercepted by an MITM attacker.

While this issue was seen in Android, it may affect other platforms.

Screenshots:

Bug Details – Credits Page

Chrome has a credits page (“chrome://credits“) that contains licensing information and links to various open source projects. Not all of these links use HTTPS, instead some use HTTP. As the result if a user is on a hostile network and taps any of these sites, the connection can be intercepted by an MITM attacker. This can be seen by going to the URL (“chrome://credits“) or going to “Help”, “About”, “Open Source Licenses”.

This impacts all platforms that Chrome supports including Linux, Windows, Android, iOS, MacOS and ChromeOS.

Screenshots:

Vendor Response

The vendor doesn’t consider these to be security bugs and they remain unfixed.

References

Chromium Bugs: 788055 and 927139

Credits

Advisory written by Y. Shafranovich.

Timeline

2017-11-22: Default sites bug (#788055) reported to the vendor
2017-11-23: Initial vendor response (#788055), not considered a security bug
2017-11-23: Vendor response (#788055)
2019-01-30: Credits bug (#927139) reported to the vendor
2019-01-30: Initial vendor response (#927139), not considered a security bug
2019-01-30: Vendor response (#927139)
2019-04-01: Checking with vendor regarding disclosure (#788055)
2019-05-27: Public disclosure for both