Collaborate Disseminate
It is recommended to do this often in web apps:
import { NextResponse } from ‘next/server’
import type { NextRequest } from ‘next/server’
// Define allowed origins
const allowedOrigins = [
‘http://localhost:3000’,
‘http://localhost:30… Continue reading How to securely allow localhost to access through CORS, without exposing it to anyone’s localhost?
I came across a site that allows the client-security-token in CORS requests:
Access-Control-Allow-Headers: …, client-security-token
I have not found any request yet that includes this header. But it also does not seem to be application-… Continue reading What is the client-security-token header typically used for?
What I have understood (I guess):
Cross-origin Cookies:
Cookies set with Domain="example.com" are not sent with fetch requests from origins like hello.example2.com to mywebsite.example.com because they are different domains. How… Continue reading Understanding Cross-Domain Cookies and `SameSite` Attributes with Express.js and Third-Party Tracking
To allow cookies to be sent to my ExpressJS server,credentials: true has to be set in my CORS config.
What potential security risks/ vulnerabilities could arise from this configuration?
If possible, how could said risks be mitigated in pra… Continue reading CORS credentials option set to true
Does the CORS asteriks / wildcard (*) include both encrypted (https) and unencrypted origins (http)? And is the null origin (i.e., when a local file is doing a xmlhttprequest, or within an iframe with sandbox attribute) regarded as http?
… Continue reading Does the CORS asteriks / wildcard include both encrypted and unencrypted origins?
From Cross-Origin Resource Sharing (CORS) – HTTP | MDN:
CORS failures result in errors but for security reasons, specifics about the error are not available to JavaScript. All the code knows is that an error occurred. The only way to dete… Continue reading What are the reasons for CORS failure errors to not be available to JS?
To help developers with integrating with our SAML/OAuth/OIDC Identity Provider on their local dev environments, I’m thinking about configuring a demo client/app in our production IdP that has localhost configured as valid redirect url (OAu… Continue reading Risks with having a "localhost" service configured on a production SAML/OAuth/OIDC Identity Provider
I have been using lots of various APIs in my frontend lately and they all have to be properly configured with CORS and the browser always do extra OPTIONS request that only make debugging harder.
I was wondering if there could be a way of … Continue reading Is prohibiting cookies a viable CORS alternative?
I was testing an internal application recently, that had fully permissive CORS, i.e. it echoes the Origin header into Access-Control-Allow-Origin, has Access-Control-Allow-Credentials: true and handles OPTIONS properly. All the pieces were… Continue reading Do browsers have a defence against CORS from internet to intranet sites?
I have a site with Access-Control-Allow-Credentials: true and it also allows me to use any origin I want, but Cookie flagged SameSite=Lax. I want to perform CSRF attack, but I need to bypass Lax somehow. Is there’s a way to do it?