Comment 32 for bug 556293

If ubuntu-system-services is setting the proxy information in apt's config already, I don't think there's actually anything more to be done here. We should definitely *not* be whitelisting the http_proxy variable for sudo, as this allows a user with restricted sudo access to mitm attack http traffic to a program running as root. While this is presumably not a security risk for the many users on this bug report who administer their own machines, the sudo config we ship must remain secure across all the various install scenarios we support. Consequently, I agree with Martin that we should not be implementing this by letting sudo pass http_proxy by default, and we appear to already handle global proxy configuration via ubuntu-system-services.