On Wed, Aug 18, 2021 at 11:36 PM Matt Menke <[email protected]> wrote:
> > > On Wed, Aug 18, 2021 at 5:23 PM Yoav Weiss <[email protected]> wrote: > >> >> >> On Wed, Aug 18, 2021 at 11:18 PM Matt Menke <[email protected]> wrote: >> >>> On Wed, Aug 18, 2021 at 4:53 PM Yoav Weiss <[email protected]> >>> wrote: >>> >>>> >>>> >>>> On Wed, Aug 18, 2021 at 8:47 PM 'Matt Menke' via blink-dev < >>>> [email protected]> wrote: >>>> >>>>> Contact [email protected] >>>>> >>>>> ExplainerNone >>>>> >>>>> Specificationhttps://url.spec.whatwg.org/ >>>>> >>>>> Summary >>>>> >>>>> Most hostnames that aren't valid IPv4 addresses, but end in numbers >>>>> are treated as valid, and looked up via DNS (e.g., http://foo.127.1/). >>>>> Per the Public Suffix List spec, the eTLD+1 of the hostname in that URL >>>>> should be "127.1". If that is ever fed back into a URLs, " >>>>> http://127.1/ <http://127.0.0.1/>" is mapped to "http://127.0.0.1/"; >>>>> by the URL spec, which seems potentially dangerous. "127.0.0.0.1" could >>>>> also potentially be used to confuse users. We want to reject URLs with >>>>> these hostnames. >>>>> >>>>> >>>>> Blink componentInternals>Network>DNS >>>>> <https://bugs.chromium.org/p/chromium/issues/list?q=component:Internals%3ENetwork%3EDNS> >>>>> >>>>> Motivation >>>>> >>>>> Most hostnames that aren't valid IPv4 addresses, but end in numbers >>>>> are treated as valid hostnames, and looked up via DNS. Example hostnames: >>>>> 127.0.0.0.1, foo.0.1, 10.0.0.09, 08.1.2.3. These can be problematic for >>>>> the >>>>> following reason: * "http://foo.127.1/"; has an eTLD+1 of "127.1", per >>>>> the public suffix list spec. If that's ever used as the hostname in a new >>>>> URL, however, as in "http://127.1 <http://127.0.0.1/>", it will then >>>>> get mapped to "http://127.0.0.1/";, per the URL spec, which is a >>>>> different host, which is not safe. * "http://127.0.0.0.1"; and " >>>>> http://1.2.3.09";, both of which are looked up via DNS rather than >>>>> failing or being treated as IPv4 hostnames, also seem potentially >>>>> confusing. While no exploit is currently known here, we want to remove >>>>> support for these as a preventative security measure. The URL spec has >>>>> been >>>>> updated so that any URL with a hostname ending in a number that's not an >>>>> IPv4 address (including, e.g., http://foo.1./, but not http://foo.1../) >>>>> is considered invalid. Since this is part of the URL spec, not the DNS >>>>> spec, we want to reject these URLs are the GURL layer, for URLs with >>>>> appropriate protocols (http, https, ws, wss, file). For consistency, we >>>>> should also fail DNS lookup attempts of these sorts of hostnames. >>>>> >>>>> >>>>> Initial public proposalhttps://github.com/whatwg/url/pull/619 >>>>> >>>>> TAG reviewNot required for an Intent to Deprecate, I believe. >>>>> >>>>> TAG review statusNot applicable >>>>> >>>>> Risks >>>>> >>>>> >>>>> Interoperability and Compatibility >>>>> >>>>> Any URL with an affected hostname will fail to load, and will need to >>>>> be migrated to another hostname. URLs of this form do appear to be in use, >>>>> though it's not clear under what circumstances. No entry in the public >>>>> suffix list is affected. Affected URLs make up no more than 0.0003% of >>>>> hostnames looked up via the host resolver on any platform, and are >>>>> basically not used in any file URLs, according to our metrics. >>>>> >>>> >>>> Do we have reason to believe these hostnames are not legitimate ones? >>>> >>> >>> Unfortunately, we have no insight into them - they could be mistyped >>> URLs sent to typo squatting ISPs that OSX lets through but the Windows host >>> resolver blocks, and various flavors of Linux treat differently. Or they >>> could be mapped via a hosts file, or they could be hostnames that only >>> resolve on public networks. Could be some network tool that uses them when >>> installed locally, but is only available on certain platforms. No reason >>> to think one possibility is more likely than the others. >>> >> >> Do we have UKM for them that would enable us to test a random sample? >> I'm concerned about blocking those hostnames if they are legitimate, as >> that's something that a web developer can't do anything about. >> So even if the number of hosts is small, I'd like to get more certainty >> that they are *not* legitimate hosts before blocking them. >> > > We have UKM on their number (0.0003% of DNS lookups on OSX, less elsewhere > - we can't meaningfully instrument percent of created GURLs), but we don't > have their hostnames, what they resolve to, or know anything else about > them, unfortunately. > > Navigation to a subset of these as frame URLs were broken at one point - > I'm pretty sure the breakage even made it to stable: > https://crbug.com/1173238. There were no reports of problems. Only > non-IPv4 URLs where the last two components were broken, though, and it > didn't affect subresources. On OSX and Android, over 99% of successfully > resolved problematic hostnames fit into that bucket, though on Linux, only > about 2% do. > > That doesn't give us any hard conclusions, except they're either not > deliberate navigations on OSX/Android, or they're not navigations. > :| One more question: Is this an intent to Prototype or an intent to deprecate? The title is a bit unclear.. > > >> >>> >>> >>>> >>>>> On OSX and Android, about 90% of host resolver lookups for these >>>>> hostnames succeed, 60% do on Linux, and 2% on Windows and ChromeOS. >>>>> >>>> >>>> Do you know where those failures are coming from? >>>> >>> >>> Could be typos, could be the Windows and ChromeOS host resolvers don't >>> let them through. Since we've had no filed bugs about them, I suspect the >>> failures are not deliberate navigations or intended network requests. I'm >>> much more interested in where the successes are coming from, myself. >>> >>> >>>> >>>> >>>>> To allow for emergency disabling in case of wider than expected >>>>> breakage, I intend to add a feature for it, and do a 50% field trial on >>>>> pre-release channels, though plan to just enable the feature, rather than >>>>> do a gradual rollout to stable, given the low usage. >>>>> >>>>> >>>>> Gecko: Positive ( >>>>> https://github.com/whatwg/url/pull/619#issuecomment-890826499 >>>>> <https://www.chromestatus.com/admin/features/launch/5679790780579840/1?intent=1> >>>>> ) >>>>> >>>> >>>> Can you file an official position request? https://bit.ly/blink-signals >>>> >>> >>> Done for Mozilla: >>> https://github.com/mozilla/standards-positions/issues/568 >>> >>> Should I also do this for WebKit as well? They have in process CLs, so >>> not sure if it's still needed. >>> >> >> Agree that in-flight patches for WebKit are a sufficient positive signal. >> >> >>> >>> >>>> >>>> >>>>> >>>>> WebKit: In development (https://bugs.webkit.org/show_bug.cgi?id=228826 >>>>> ) >>>>> >>>>> Web developers: No signals >>>>> >>>>> Activation >>>>> >>>>> This breaks anything using one of these domains, and requires >>>>> migrating to other hostnames. >>>>> >>>>> >>>>> Security >>>>> >>>>> None >>>>> >>>>> >>>>> Debuggability >>>>> >>>>> These will act like any other invalid URL. Behavior is context >>>>> dependent. Since this is logic deep within GURL, and GURLs are created in >>>>> a >>>>> great many places, console warnings specifically for this seem not >>>>> practical. >>>>> >>>>> >>>>> Is this feature fully tested by web-platform-tests >>>>> <https://chromium.googlesource.com/chromium/src/+/master/docs/testing/web_platform_tests.md> >>>>> ?No. Javascript URL construction is tested, but URLs are used in a >>>>> great many other places, which don't have test coverage, since DNS lookups >>>>> for these domains must succeed in the first place for the tests to be >>>>> meaningful. >>>>> >>>>> Flag name >>>>> >>>>> Requires code in //chrome?False >>>>> >>>>> Tracking bughttps://crbug.com/1237032 >>>>> >>>>> Estimated milestones >>>>> DevTrial on desktop 95 >>>>> DevTrial on Webview 95 >>>>> >>>>> Link to entry on the Chrome Platform Status >>>>> https://www.chromestatus.com/feature/5679790780579840 >>>>> >>>>> This intent message was generated by Chrome Platform Status >>>>> <https://www.chromestatus.com/>. >>>>> >>>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "blink-dev" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to [email protected]. >>>>> To view this discussion on the web visit >>>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAEK7mvq%2Bfnau%3DE%2BONhe0kr9HOpN84eCpoub84%3DswKzPkrGzi5A%40mail.gmail.com >>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAEK7mvq%2Bfnau%3DE%2BONhe0kr9HOpN84eCpoub84%3DswKzPkrGzi5A%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> >>>> -- You received this message because you are subscribed to the Google Groups "blink-dev" group. 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