Superhuman (formerly Grammarly) · Report #412490
Permissive CORS policy trusting arbitrary extensions origin
Validstatus
mediumseverity
$500bounty
33upvotes
6 Nov 2019disclosed
Summary
@foobar7 identified that misconfigurations in CORS and CSRF handling allowed malicious browser extensions, which have permission to interact with grammarly.com domain, to impersonate the user.
The vulnerability was resolved with improved CSRF/CORS handling.
How it was found
The write-up for this report has not been downloaded yet, or the program disclosed it without one. Read it on HackerOne.