HackerOne users: Testing against this community violates our program's Terms of Service and will result in your bounty being denied.

External links entered without https are changed to unsafe

edited February 2020 in Vanilla 3.x Help

Vanilla version: 3.3

If I use the rich editor to link to a site where it says "Paste or input URL" and include https in URL, all is fine.

If I omit the protocol or link to a http site, vanilla changes the URL protocol to unsafe and therefore doesn't work.

OK

Not OK

My site is running perfectly fine under SSL but I don't know how/why external links are getting changed like this? Why would someone visiting a http external site from my forum be considered unsafe?

Same thing seems to be happening here. Why?

Comments

  • R_JR_J Ex-Fanboy Munich Admin

    Can you please create an issue on GitHub for that? I can't imagine that this is intended behaviour.


  • I am sure there was some reasoning behind it, although the conclusion is a bit unexpected ... maybe a plugin can change it..

    In vanilla-3.3\library\core\class.format.php

    const SAFE_PROTOCOLS = [
        "http",
        "https",
        "tel",
        "mailto",
    ];
    
    
    /**
     * Sanitize a URL to ensure that it matches a whitelist of approved url schemes.
     * If the url does not match one of these schemes, prepend `unsafe:` before it.
     *
     * Allowed protocols
     * - "http:",
     * - "https:",
     * - "tel:",
     * - "mailto:",
     *
     * @param string $url The url to sanitize.
     *
     * @return string
     */
    public static function sanitizeUrl(string $url): string {
        $protocol = parse_url($url, PHP_URL_SCHEME) ?: "";
        $isSafe = in_array($protocol, self::SAFE_PROTOCOLS, true);
    
        if ($isSafe) {
            return $url;
        } else {
            return "unsafe:".$url;
        }
    }
    
  • edited February 2020

    Ok so the main issue here then is when you don't enter a protocol at all, it doesn't get rewritten as http or https, but unsafe.

  • R_JR_J Ex-Fanboy Munich Admin

    @donshakespeare I really expect that this must be considered a UX bug. Just yesterday I have produced such an unclickable link here.

    I know that a valid link technically requires the protocol, but as a user my expectation is that what I enter into the address line of my browser is the link and that I can enter that into that "Link" popup and everything is fine.


    donshakespearerbrahmson
  • edited February 2020

    Yes it is very unpleasant and unexpected indeed. I suggest that if the reasons for this implementation exist and bars the idea of bug, then at least we need a way to easily configure the accepted protocols.

    I often don't know the protocol of the site's address I am typing from memory. I expect this behaviour to default to blank protocol and let the browser figure it out.

    Seems Angular2 is also notorious for this:

    https://stackoverflow.com/questions/15606751/angularjs-changes-urls-to-unsafe-in-extension-page

    https://serviceportal.io/avoid-unsafe-prefix-links/

  • rbrahmsonrbrahmson "You may say I'm a dreamer / But I'm not the only one" NY ✭✭✭

    I'm not sure what's the downside to prepend http or https (choice could be in config) in any protocol lacking input that's is expected to have one. Therefore I tend to concur that short of clarification by the Vanilla team this is a bug.

    When I write plugins I am using the above assumption (e.g. FeedDiscussionPlus).

  • charrondevcharrondev Developer Lead (PHP, JS) Montreal Vanilla Staff

    Yeah, we could probably be a bit smarter about it. I'm not opposed to changing the behaviour to switch to append https:// instead of unsafe.

    I think we also have an allowed safe protocol group that's configurable, and just doesn't happen to be used here. I think this ended up being put in as a quick security patch, and didn't get as much thought as it probably should have.

    rbrahmson
Sign In or Register to comment.