Dio: Cross-origin redirect leaks sensitive request headers in `dio_http2_adapter`

[ Why it matters ]Priority signals

• Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

Dio is a powerful HTTP client for Dart and Flutter. From 1.0.0 until 2.8.0, dio_http2_adapter follows redirects in Http2Adapter._fetch by copying the original RequestOptions.headers into the redirected HTTP/2 request without comparing the source and destination origins. A server contacted by an application can return a cross-origin Location redirect to a different-origin destination, which then receives preserved Authorization, Cookie, and Proxy-Authorization headers because RequestOptions.copyWith retains the full header map. The issue applies when applications use Http2Adapter for authenticated requests, and redirect following is enabled by default. This issue is fixed in version 2.8.0.

[ Fixes ]Fixes and patches

• dio_http2_adapter 2.8.0Fixed version · GitHub Advisories · pub package dio_http2_adapter: upgrade to 2.8.0 or later (affected >= 1.0.0, <= 2.7.1)

[ Packages ]Affected open-source packages

• dio_http2_adapter pubAffected >= 1.0.0, <= 2.7.1 · fixed in 2.8.0 · GHSA-cr65-55v9-xhvv

[ References ]References

• github.com/cfug/dio/commit/9d7ac913340084f3b4987b121e076f28d637a81e
• github.com/cfug/dio/releases/tag/http2_adapter_v2.8.0
• github.com/cfug/dio/security/advisories/GHSA-cr65-55v9-xhvv