Bumping this old thread as it discussed the issue of Safe zone Chromium not being up to date, among other things.
pk explained:
@NiveusLuna, I agree with you, but it's quite hard to do. Avast7 should use Chromium 15.x version (last known) and every time we get a Chromium build we have to do a lot of changes (add our DNS protection, disable a lot of components, plugins, etc). Since it's little automatized, we can't do that everytime when we release a new avast build (stand-alone SafeZone browser has approx. 30Mb and it's quite a lot for regular antivirus updates).
I well see your reasons, but the current [August 2015] Chromium in Safe zone is Version 38.0.2078.1 (280821),
which dates back to more than one year ago!, according to Chromium version history.
https://en.wikipedia.org/wiki/Chromium_(web_browser).
Like NiveusLuna noticed, old browser versions would have security holes which have since been fixed in newer releases.