I have these two inline script tags:
<script async defer src="https://apis.google.com/js/api.js"></script>
<script async defer src="https://accounts.google.com/gsi/client"></script>
note: I tried specifying both the host only (https://apis.google.com) and the full URL.
And I added the following CSP header:
<meta http-equiv="Content-Security-Policy"
content="script-src 'self' https://apis.google.com/js/api.js https://accounts.google.com/gsi/client">
This is supposed to allow me to include scripts from the origin and said two sources. However, I still receive the following error:
The problem is most likely that there are now two or more policies active. They can be defined in both meta tags and as response headers. Any content needs to pass all policies, and adding another policy can only make it stricter. One policy is "script-src 'self'" while your policy is "script-src 'self' https://apis.google.com/js/api.js https://accounts.google.com/gsi/client". Combined they will be equal to the first one. You need to figure out where the other policy is set and modify or disable it. It could be set by a framework, webserver, proxy, load balancer etc...
Related
I'm running vue3 app using vite.
I want to add this script <script src="https://js.stripe.com/v3"></script> to my index.html; in order to handle payments with Stripe.
But I face these error in console:
VM262:5 Refused to execute inline script because it violates the following Content Security Policy directive: "script-src 'self'". Either the 'unsafe-inline' keyword, a hash ('sha256-GEy81O1cBXMUtzNmiNgydJFrTMOlLkoqKvaHpNDLcrA='), or a nonce ('nonce-...') is required to enable inline execution.
I did some couple of researches and with the help of official documentation; find out that we need to add meta tag that allows this action:
<meta
http-equiv="Content-Security-Policy"
content="connect-src 'self' https://api.stripe.com ws://127.0.0.1:3000; frame-src 'self' https://js.stripe.com https://hooks.stripe.com; script-src 'self' https://js.stripe.com 'unsafe-inline'"
/>
But nothing changes...
First of all, why CSP is enabled in my project (Because I didn't see same problem in Stripe videos in Youtube) and then how can I fix that?
Thanks
I am trying to load jQuery in Electron (v. 16.0.0), but I get this error:
Inside the head element I have included this line:
<meta http-equiv="Content-Security-Policy" content="script-src 'self';">
Also, inside the body element, I am trying to load jQuery like this:
<script src="https://code.jquery.com/jquery-3.6.0.min.js" integrity="sha256-/xUj+3OJU5yExlq6GSYGSHk7tPXikynS7ogEvDej/m4=" crossorigin="anonymous"></script>
I have tried so many ways to find a solution for this, but to no avail. Previously, I also tried to load jQuery like this, but it gave me a similar error, shown below:
<script>window.$ = window.jQuery = require('./libraries/jQuery/jquery.min.js');</script>
Answers to a related question did not work for me either. What should I do?
The reason Electron, or any other Web browser that implements Content Security Policy, for that matter, would correctly refuse to load a script from an arbitrary origin (URL), or even an "inline" script (e.g. script text inside a script element), is because your security policy is explicitly specified to deny such attempts, with that meta element you said you added:
<meta http-equiv="Content-Security-Policy" content="script-src 'self';">
Why did you add it? Was it there by someone else's hand? Why is it there? It's the reason why Electron denies loading of the scripts in question.
The value of the content attribute above has the effect of instructing Electron to only allow loading scripts from the same origin as the origin of the document containing the meta element. That effectively excludes every other origin like https://code.jquery.com and inline scripts (which have to be allowed explicitly in this case because self denies these). Basically, the value is to be interpreted as "only allow loading scripts from the same site". Inline scripts are not considered as "same site".
Simpler put, you yourself prohibit loading of scripts from the kind of locations you then attempt to use, with that meta element.
You need to learn how Content Security Policy mechanism works and applies in your case. You will have to decide whether you want to allow loading of scripts from domains like code.jquery.com, or whether, for example, you will only want to allow loading scripts from your website, which in turn will probably necessitate you copying the JQuery library you want to use to be served by your website. You also will have to decide if you want to allow "inline" scripts on your site, for whatever reason you may consider necessary.
The security policy mechanism itself is very useful, don't shy away from it, it's there for a reason -- to help you prevent abuse of your site users by malicious scripts loaded by other malicious scripts or mechanisms. But you need to use it correctly, obviously.
You have 2 issues because of jQuery:
script-src 'self' does not allow to load script from https://code.jquery.com/jquery-3.6.0.min.js, that's why you observe Refused to load the script 'https://code.jquery.com/jquery-3.6.0.min.js'... error.
You have to adjust your CSP at least as script-src 'self' https://code.jquery.com;.
After page loads, the jQuery pick up all scripts having $() and place them into one inline script in the <head> section. That's why you observe Refused to execute inline script ... error.
This inline script can be resolved with either 'unsafe-inline' or 'unsafe-eval' or 'nonce-value'(for jQuery > 3.4).
Allowing 'unsafe-inline' is a very harmful advice, since such CSP will not protect against XSS at all (https://youtu.be/zlH_bBQMgkc?t=717).
Also Electron does not have the technical ability to refresh the 'nonce' value.
Therefore, the most secure CSP you can do is:
script-src 'self' 'unsafe-eval' https://code.jquery.com;
or much better:
default-src 'self'; script-src 'self' 'unsafe-eval' https://code.jquery.com;
Note: Contrary to a common misconception, 'self' does not mean the Same Origin Policy, CSP interprets 'self' much more broadly.
I want to access a website using javascript. but I am getting the following error in the console.
Refused to connect to 'https://example.com' because it violates the following Content Security Policy directive: "default-src 'self'". Note that 'connect-src' was not explicitly set, so 'default-src' is used as a fallback.
I have added the following meta tag in the index.html,
meta http-equiv="Content-Security-Policy" content="connect-src 'self' http://example.com;" />
Isn't this the right way to add CSP? please help.
You already have one CSP published with the default-src 'self' policy. Quite possible it was done via HTTP header.
Check the Helmet middleware settings in case of NodeJS server, or Header set in the .htaccess file in case on Apache server. In case of Nginx it can be add_header in the config.
By adding <meta> tag you just publish a second CSP, which does not overrides the first one. 2 CSPs works subsequently - all sources should pass both CSP.
Figure out where CSP is publushed and add connect-src 'self' http://example.com; there.
In ExpressJS, the HTML file is loaded as follows,
app.use(express.static(__dirname + '/src/templates/'));
And in the HTML, this is my meta tag with Content Security Policy,
<meta http-equiv="Content-Security-Policy" content="default-src 'self' https://cdnjs.cloudflare.com 'unsafe-inline' 'unsafe-eval' fonts.gstatic.com fonts.googleapis.com kit.fontawesome.com; img-src 'self' data:; object-src 'none'; require-trusted-types-for 'script'; script-src 'self' cdnjs.cloudflare.com">
I'm trying to load the following JS files from external sources,
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<script src="https://kit.fontawesome.com/a4ff515084.js" crossorigin="anonymous"></script>
but I've specified them in the CSP meta tag, but still, I'm getting the following error and the external JS files are not getting loaded.
and I can see some issues,
Any help on this would be greatly appreciated.
You have 2 Content Security Policies at the same time:
the first one through <meta http-equiv="Content-Security-Policy" content="...">
the second one is published by Helmet 4 (it has default CSP enabled).
Directive rules from multiple CSPs are combine with logical "AND" therefore more restrictive CSP is acts.
Use Helmet to configure CSP HTTP header (preferred way), or use meta tag, bot not both at the same time.
I have the Content Security Policy:
default-src 'none';
style-src 'self';
script-src 'self' https://www.google-analytics.com;
img-src 'self' https://www.google-analytics.com;
connect-src 'self';
On my page I have put the inline GA code into an async script:
<script src="/javascript/ga.js" async></script>
This causes a CSP error:
Refused to load the script 'data:application/javascript;base64,KGZ1bmN0aW9uKCkgewoJLy8gaHR0cHM6Ly9kZXZl…07Cgl9OwoJZ2EucmVtb3ZlID0gbm9vcGZuOwoJd2luZG93W2dhTmFtZV0gPSBnYTsKfSkoKTs=' because it violates the following Content Security Policy directive: "script-src 'self' https://www.google-analytics.com".
Is there any way to serve this script from a JS file, and if not how would I need to change the CSP?
Google Analytics is CSP-compatible. The base64-encoded data: blob OP is seeing is being injected by the uBlock Origin extension. To verify, disable it/try incognito. IIRC, this is due to an "experimental/unbreak" setting in the extension.
Please resist the temptation to whitelist data: in script-src. That would make the policy completely useless for XSS mitigation, since an attacker could just inject <script src="data:text/javascript,alert(1)"></script> to execute Javascript.
Please see Michele Spagnuolo's answer and upvote.
This is caused by uBlock Origin and it is because data URLs are not whitelisted:
script-src data:;
There is no point in doing this as this could leave your application vulnerable should untrusted data be used as URLs anywhere within your application, or if the attacker can inject tags that use such URLs. This of course depends on the injection point and which characters are allowed.
Of course you should be whitelisting any user entered URLs (e.g. make sure they start with http:// or https://), however as CSP is defence-in-depth measure you probably don't want to weaken it too much.
The upshot is that you're weakening your CSP by doing this in order to prevent a CSP report or error from being triggered.