I've just started seeing this with my embedded youtube videos on Chrome (86.0.4240.193 - recently updated which is probably why I'm just seeing this) - these are 'reports' only, so the videos still show but 100s of errors can't be right! This is what I'm seeing:
[Report Only] Refused to evaluate a string as JavaScript because 'unsafe-eval' is not an allowed source of script in the following Content Security Policy directive: "script-src 'strict-dynamic' 'unsafe-inline' https: 'report-sample' 'nonce-t9IE7nI2leo7qKxsm7d80g=='".
Here's my iFrame --
<iframe id="video-iframe" width="500" height="281" src="https://www.youtube.com/embed/HIDDENVIDEO" frameborder="0" allowfullscreen ></iframe>
I cannot figure out what the CSP should be -- here's one that I found that apparently solved their problem --
<iframe id="video-iframe" width="500" height="281" src="https://www.youtube.com/embed/HIDDENVIDEO" frameborder="0" allowfullscreen csp="script-src 'self' https://www.google-analytics.com/ https://www.youtube.com/ https://s.ytimg.com/; object-src 'self'; child-src https://www.youtube.com/* https://s.ytimg.com/"></iframe>
Not so much -- I just see: Refused to display....
Any help much appreciated.
I just checked the developers.google.com/youtube/iframe_api_reference#Examples page and I'm seeing the same thing -- surely this shouldn't be happening, right?
As you can see, this error is triggered not your CPS - your's do not have 'nonce-t9IE7nI2leo7qKxsm7d80g=='" token. This error appears within Google's <iframe> and it's totally Google's internal deal.
The fact is that several previous versions of Chrome had a bug and did not block eval expressions.
In version 86 Chrome, they fixed this bug, and to verify this, they set the Report-Only header and made a fake call to eval to see reports.
CSP for Youtube is very simple and does not require 'unsafe-eval', because all works within isolated iframe:
frame-src youtube.com www.youtube.com; is enough to allow for Youtube in iframe.
By the way, your CSP has an error - the * is not allowed in path-part. And be careful with <iframe csp= - if server does not agree with your CSP, content will be blocked.
But this <iframe csp= played the role because of once more Chrome bug - it ignores Content-Security-Policy-Report-Only if Content-Security-Policy header presence.
I was able to get my embedded videos working using a meta tag in the <head>
<meta http-equiv="Content-Security-Policy"
content="default-src 'self'; img-src https://*; child-src 'none'; frame-src youtube.com https://www.youtube.com;">
add the https:// to www.youtube.com
Related
I am working on Drupal 9.3.8 site and using CSP module to setup the CSP header.
There are few core dependencies or contrib modules which require unsafe-inline in CSP header but scanner recommends not the have unsafe-inline, so looking for the fix to remove the use of unsafe-inline.
Dependencies that require unsafe-inline:
Drupal core ckeditor, modernizer and AJAX calls - which can be handled by CSP module used above which adds unsafe-inline only when ckeditor renders, but not when only modernizer is required.
Google Analytics module - which adds the script inline instead of putting it in a file and include it on each page. We have the patch compatible with D7 but not for D8/9.
AntiClickJack snippet which is as below:
<style id="antiClickjack">body{display: none !important;}</style>
Solutions:
Installed and setup CSP module as mentioned above to handle Drupal core libs/dependencies requirement.
To handle only rendering of modernizer.js and unsafe-inline, will need customization to the CSP module.
For antiClickJack and google analytics script and style tags, cannot add hash or nonce as unsafe-inline will be ignored which will break the handling of Drupal core requirements
CSP header that I have is as below:
Content-Security-Policy: default-src 'self'; connect-src 'self' www.google-analytics.com; frame-src 'none'; img-src 'self' data: https://www.google-analytics.com; object-src 'none'; script-src 'self' www.googletagmanager.com www.google-analytics.com ajax.googleapis.com 'unsafe-inline'; script-src-elem 'self' www.googletagmanager.com www.google-analytics.com ajax.googleapis.com; style-src 'self' 'unsafe-inline'; frame-ancestors 'none';
Questions:
How to handle antiClickJack snippet to avoid the use of unsafe-inline?
Do we have a customized approach to add the google analytics script to a file instead of adding it inline?
Add the following hash to your style-src: 'sha256-NHgJfLahpnqTyd+gTNfZfM2wjTUfB3Wk1CvqZfZpeHY=' Most browsers will suggest a hash for you, or you can use https://report-uri.com/home/hash. Note that the hash works as long as the content is unchanged, so only use it for static code.
Google Analytics and Google Tag Manager are not easy to implement without 'unsafe-inline'. You might be able to move to a file, but I don't know if that has an impact on the order of events. You will also need to look into CSP nonces for the code they insert. You will need to configure them to use your nonce and make sure that a new nonce is created for every page load. My experience is that setting a custom value for the nonce and change it for every page load is not trivial or possible within some frameworks, but worth giving a try.
I have ASP.NET Core application and i am using Telerik's UI for ASP.NET Core framework for certain widgets like Date, DropDownList, Charts etc.
Application is loading all javascripts, images, css from its own server. So i have enabled CSP policy as below
script-src 'self' 'unsafe-eval';
style-src 'self' 'unsafe-inline';
img-src 'self' data:;
font-src 'self';
media-src 'none';
object-src 'none';
child-src https://xxxx.yyyy.com;
report-uri http://myapplication/csp/report;
However when the page load i see error in chrome's console
Refused to execute inline script because it violates the following
Content Security Policy directive: "script-src 'self' 'unsafe-eval'".
Either the 'unsafe-inline' keyword, a hash
('sha256-oii70XYoqukWS9204nbwatxgYOYcr06+rftc4egdfUk='), or a nonce
('nonce-...') is required to enable inline execution
this error is repeated for several Kendo widgets that i'm using on that page. For example date widget. In cshtml i have configured date as below
#(Html.Kendo().DatePicker()
.Name("sbDate")
.HtmlAttributes(new { #class = "mydate" }))
which gets render in html as
<input class="mydate" id="sbDate" name="sbDate" type="date" value="" /><script>jQuery(function(){jQuery("#sbDate").kendoDatePicker({"format":"M/d/yyyy","footer":false});});</script>
I have already gone through Telerik's suggestion here and here for CSP. And as per the suggestion i only i have to add unsafe-eval to get widgets working. However looks like that is not true. I also have to add unsafe-inline to get widgets working.
But the whole point of enabling CSP is to not allow inline scripts.
Questions
Is there any way to solve this issue?
Update 1
Widgets only works in IE 11 without adding unsafe-inline. In chrome and IE edge widget requires unsafe-inline to work.
The solution below might work (i have not tried yet)
1> Add Deferred method for each kendo widget. Like
#(Html.Kendo().DatePicker().Name("BeginDate").Deferred())
2> In each view that is using Kendo control, at the bottom add the script tag
<script asp-add-nonce="true">
#Html.Kendo().DeferredScripts(false)
</script>
Note that asp-add-nonce is not out of the box from asp.core. You have to install Joonasw.AspNetCore.SecurityHeaders nuget library. I found this article from the author that shows how to configure CSP for .net core application and also how to generate new nonce for each request.
3>Dont configure CSP policy in web.config because we need different nonce value for each request, instead configure the CSP policy using Joonasw.AspNetCore.SecurityHeaders middleware as mentioned in the article.
4>I thinks we don't need to add unsafe-inline if we use random nonce (unless you are targeting to older browsers)
I can't really tell if this would solve your issue, but in our Application, we are using the Deferring feature, but for other reasons. Our reason is that we load all scripts (esp. jquery.js) at the end of the page. But the side effect is that no jQuery script calls are rendered into the page anymore. You can control the place to generate all scripts by executing #Html.Kendo().DeferredScripts() (but you will find more help in the docs above). Anyway, probably in the context of CSP, even that <script> block at the very end of the page is still considered "inline". But give it a try.
Safari 10 throws a CSP-style-src-Violation in spite of calling a weg page with no style attributes inside.
The violation-message is:
Refused to apply a stylesheet because its hash, its nonce, or
'unsafe-inline' does not appear in the style-src directive of the
Content Security Policy.
Test web page is:
CSP test page
The only addon installed is Adblock-Plus. After removing the addon, the violation is not shown anymore. The rendered html source shows no style-attribute at all, with adblock or without.
Is there a way how to filter out these false violation messages?
They are misleading.
I have also faced the same issue.looks like if you mention the style directive its expecting style-src 'self' 'unsafe-inline'; hope it helps.
The Zemanta Chrome Extension fails to load with the following error message
loader.js:13 Refused to load the script 'https://static.zemanta.com/widgets/blogger.com/merged-blogger.js?v=1451290656'
because it violates the following Content Security Policy directive:
"script-src 'self' *.google.com *.google-analytics.com 'unsafe-inline'
'unsafe-eval' *.gstatic.com *.googlesyndication.com *.blogger.com
*.googleapis.com uds.googleusercontent.com https://s.ytimg.com
www-onepick-opensocial.googleusercontent.com www-bloggervideo-opensocial.googleusercontent.com
www-blogger-opensocial.googleusercontent.com *.blogspot.com https://www.blogblog.com".
I have changed the content_securiy_policy line to the following, and reload the extension
"content_security_policy": "script-src 'self' https://ssl.google-analytics.com https://*.zemanta.com; object-src 'self'"
Why is it that "https://*.zemanta.com" is not listed in the CSP directive in the error message above, and how can I make sure it is in the CSP?
It looks like an error thrown by a webpage with its own CSP, not inside your extension. So the CSP you set there has no effect.
It probably happens as a result of a content script trying to insert <script src="..."> into the page. That's subject to the page's CSP and can fail.
You can try to bypass the page's CSP by loading the script with XHR and inserting a <script> tag with the code included instead of src link. Note that this may fail at a later stage, since while the script will be executed this way, it will be subject to CSP in its own actions (so if it, say, tries to add a <script> tag as well, it will fail).
Alternatively, you could use webRequest API to intercept and modify the CSP header. That's risky since you're loosening the page's security in general.
I'm trying to use Firebase in a Chrome extension background page, but it looks like it's executing inline-scripts, which isn't allowed because of security concerns.
I've currently set the CSP to:
{"content_security_policy":
"script-src 'self' https://cdn.firebase.com https://<my-subdomain>.firebaseio.com; object-src 'self'"}
I'm able to load the initial Firebase script, but upon calling new Firebase('my-firebase-url'), I get the following error:
Refused to execute inline script because it violates the following
Content Security Policy directive: ". Uncaught
ReferenceError: pRTLPCB is not defined
Is there any work around or advice the Firebase team (or anyone) can give, and maybe an explanation of why scripts are being executed inline?
At the time the question was asked, there was a bug preventing Firebase from working in Chrome extensions, but this has now been fixed.
The correct CSP is:
"content_security_policy": "script-src 'self' https://cdn.firebase.com https://*.firebaseio.com; object-src 'self'"
(Note that the wildcard in the domain is important, since Firebase may connect to other subdomains internally.)
For a sample chrome extension using Firebase, see: https://github.com/firebase/firebase-chrome-extension.
I'm having a similar problem; you see, Firebase's constructor seems to perform some dom manipulation in order to do some scripting (vague, I know), which triggers Chrome CSP because well, you are not supposed to do that.
I even trying to wrap the constructor through the Sandbox Pages, but without success (I get an DOM ERR 18, even though my manifest has all permissions). Same happens if you try to do it in a Background Page or a Popup Page for a Page Action/Browser Action.
Alternative? You can inject Firebase as a content script (do it from your manifest), and through Message Passing send the callbacks as Chrome.extension.sendMessage. I'm exactly doing this at the moment, so I can tell you how that goes, so far, at least the Firebase constructor works.
Solution? James Tampling reads this and prompts the Firebase team to look up after this :)
UPDATE: Injecting Firebase.js as a Content Script doesn't work neither, but the good news is that the Firebase team (reach Andrew Lee) is checking it out.
UPDATE 2 Firebase team fixed it, and now it does work from a Popup page (both in a Browser Popup or a Page Action one). You need to add the following CSP in your manifest.json though "content_security_policy": "script-src 'self' 'unsafe-eval' https://cdn.firebase.com https://*.firebaseio.com https://*.firebaseio.com; object-src 'self'; " It works wonders after that.
I have a cordova js app, only the below one worked:
<meta http-equiv="Content-Security-Policy" content="
default-src 'self' data: gap: https://ssl.gstatic.com 'unsafe-eval';
script-src 'self' https://www.gstatic.com https://cdn.firebase.com https://*.firebaseio.com; object-src 'self';
" />
hope this helps.