All the vulnerabilities related to the version 2.0.4 of the package
Denial of service in http-proxy-middleware
Versions of the package http-proxy-middleware before 2.0.7, from 3.0.0 and before 3.0.3 are vulnerable to Denial of Service (DoS) due to an UnhandledPromiseRejection error thrown by micromatch. An attacker could kill the Node.js process and crash the server by making requests to certain paths.
http-proxy-middleware can call writeBody twice because "else if" is not used
In http-proxy-middleware before 2.0.8 and 3.x before 3.0.4, writeBody can be called twice because "else if" is not used.
http-proxy-middleware allows fixRequestBody to proceed even if bodyParser has failed
In http-proxy-middleware before 2.0.9 and 3.x before 3.0.5, fixRequestBody proceeds even if bodyParser has failed.