Miniflux vulnerabilities

Miniflux 2.3.0 through 2.3.3 contains a server-side request forgery vulnerability that allows authenticated users to reach internal addresses by setting a feed's proxy_url. Attackers can point proxy_url at loopback or internal hosts, bypassing FETCHER_ALLOW_PRIVATE_NETWORKS checks to probe internal ports and send proxy-style requests to internal services.

Miniflux 2 prior to 2.3.1 accepts redirect targets containing backslashes, which browsers normalize to forward slashes. An unauthenticated attacker can exploit this in the login flow to redirect a victim to an attacker-controlled external site, bypassing relative-path and host checks.

Miniflux 2 is an open source feed reader. Versions 2.2.14 and below treat redirect_url as safe when url.Parse(...).IsAbs() is false, enabling phishing flows after login. Protocol-relative URLs like //ikotaslabs.com have an empty scheme and pass that check, allowing post-login redirects to attacker-controlled sites. This issue is fixed in version 2.2.15.