Servify Express is a Node.js package to start an Express server and log the port it's running on. Prior to 1.2, the Express server used express.json() without a size limit, which could allow attackers to send extremely large request bodies. This can cause excessive memory usage, degraded performance, or process crashes, resulting in a Denial of Service (DoS). Any application using the JSON parser without limits and exposed to untrusted clients is affected. The issue is not a flaw in Express itself, but in configuration. This issue is fixed in version 1.2. To work around, consider adding a limit option to the JSON parser, rate limiting at the application or reverse-proxy level, rejecting unusually large requests before parsing, or using a reverse proxy (such as NGINX) to enforce maximum request body sizes.

Affected: npm: servify-express

### Impact The Express server uses `express.json()` without a size limit, which can allow attackers to send extremely large request bodies. This may lead to excessive memory usage, degraded performance, or process crashes, resulting in a Denial of Service (DoS). Any application using the JSON parser without limits and exposed to untrusted clients is affected.

### Patches This issue is not a flaw in Express itself but in configuration. Users should set a request-size limit when enabling the JSON body parser. For example: `app.use(express.json({ limit: "100kb" }));`

### Workarounds Users can mitigate the issue without upgrading by: - Adding a `limit` option to the JSON parser - Implementing rate limiting at the application or reverse-proxy level - Rejecting unusually large requests before parsing - Using a reverse proxy (such as NGINX) to enforce maximum request body sizes