GHSA-5gjg-jgh4-gppm: 
vulnerability analysis and mitigation

The vulnerability (GHSA-5gjg-jgh4-gppm) affects the github.com/ecnepsnai/web package, specifically impacting versions 1.4.0 to 1.5.2. Discovered and disclosed on December 30, 2020, this security issue involves WebSocket requests failing to execute AuthenticateMethod calls, potentially leading to authentication bypass scenarios. The vulnerability specifically affects implementations using Web Sockets with an AuthenticateMethod, while users who don't use web sockets or don't require authentication are not at risk (GitHub Advisory).

The vulnerability stems from a failure in the WebSocket implementation where the AuthenticateMethod function, when supplied to handle options, is not called during WebSocket connections. This results in the UserData being nil in request methods, contrary to expected behavior. The issue is classified with CWE-304 and has been assigned a moderate severity rating. The vulnerability was later also tracked as GO-2021-0107 and CVE-2021-4236 (Go Vulnerability, GitHub Advisory).

The vulnerability can lead to two primary security concerns: a potential denial-of-service condition or privilege escalation in applications using the affected package with WebSocket authentication. When the UserData is accessed with the expectation of it being non-nil, the application may panic. Additionally, the authentication bypass could allow unauthorized access to protected WebSocket endpoints (GitHub Advisory).

The vulnerability was patched in version 1.5.2 of the package, which properly implements the authentication method call for WebSocket requests. Users are strongly advised to upgrade to version 1.5.2 or later. As a temporary workaround, developers can implement the authenticate method as a named function and explicitly call it at the start of the WebSocket handle method, rejecting connections when the return value is nil (GitHub Advisory, GitHub Commit).