Description
An Origin Validation Error in the elysia-cors library thru 1.3.0 allows attackers to bypass Cross-Origin Resource Sharing (CORS) restrictions. The library incorrectly validates the supplied origin by checking if it is a substring of any domain in the site's CORS policy, rather than performing an exact match. For example, a malicious origin like "notexample.com", "example.common.net" is whitelisted when the site's CORS policy specifies "example.com." This vulnerability enables unauthorized access to user data on sites using the elysia-cors library for CORS validation.
References
github.com/elysiajs/elysia-cors/blob/main/src/index.ts
github.com/elysiajs/elysia-cors/tree/main
medium.com/...ass-in-popular-opensource-library-ad27fb41e16a
