GHSA-4c8g-jvcx-v4hv
Deno: process.loadEnvFile() bypasses env permission checks and mutates process.env with only read access
Packages
Details
As written in the advisory (Markdown source, shown as plain text).
## Summary
In Deno, environment access is gated by the `env` permission. You can deny it
with `--deny-env`, or restrict it to a specific allowlist with
`--allow-env=FOO,BAR`. The expectation is that a program running without `env`
permission cannot change `process.env`.
`process.loadEnvFile()` (the Node-compatible API for loading variables from a
`.env` file) does **not** honor this. It only checks that the program has
**read** permission for the dotenv file, then writes every key in that file
into the process environment — even when `env` access is denied.
In effect, **`--allow-read` plus a writable or attacker-controlled `.env` file
is enough to defeat `--deny-env`.**
## Am I affected?
You are potentially affected if **all** of the following are true:
1. You run Deno **v2.3.0 or newer**.
2. Your program (or any dependency it imports) calls `process.loadEnvFile()`
from `node:process`.
3. You rely on Deno's permission model — specifically `--deny-env`, an
`--allow-env=…` allowlist, or running without granting `env` — as a
security boundary.
4. The `.env` path passed to `loadEnvFile()` can be controlled or modified by
a less-trusted party (untrusted input, user-writable directory, third-party
dependency, etc.) and is covered by your `--allow-read` grant.
If your program does not use `process.loadEnvFile()` at all, or if it already
grants full `env` access, this advisory does not change your risk.
References
External links from the advisory. They lead to third-party sites.