GitHub Advisoryadvisory · crates.io

GHSA-7w8p-chxq-2789 Deno.env.toObject() ignores the variables listed in --deny-env and returns all environment variables

MEDIUM Published 2025-06-04 Modified 2025-07-02 Official page ↗
Aliases
CVE-2025-48934
Ecosystem
crates.io
Packages
deno, deno_runtime
Severity
Moderate
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Weaknesses
CWE-201
Reviewed
2025-06-04

Affected packages

• crates.io deno: < 2.1.13 → fixed in 2.1.13 • crates.io deno: >= 2.2.0, < 2.2.13 → fixed in 2.2.13 • crates.io deno_runtime: < 0.212.0 → fixed in 0.212.0

Description

Summary The Deno.env.toObject method ignores any variables listed in the `--deny-env` option of the `deno run` command. When looking at the documentation of the `--deny-env` option this might lead to a false impression that variables listed in the option are impossible to read. PoC ``` export AWS_SECRET_ACCESS_KEY=my-secret-aws-key Works as expected. The program stops with a "NotCapable" error message echo 'console.log(Deno.env.get("AWS_SECRET_ACCESS_KEY"));' | deno run \ --allow-env \ --deny-env=AWS_ACCESS_KEY_ID,AWS_SECRET_ACCESS_KEY - All enviroment variables are printed and the --deny-env list is completely disregarded echo 'console.log(Deno.env.toObject());' | deno run \ --allow-env \ --deny-env=AWS_ACCESS_KEY_ID,AWS_SECRET_ACCESS_KEY - ``` The first example using `get` exits with the following error: ``` error: Uncaught (in promise) NotCapable: Requires env access to "AWS_SECRET_ACCESS_KEY", run again with the --allow-env flag console.log(Deno.env.get("AWS_SECRET_ACCESS_KEY")); ^ at Object.getEnv [as get] (ext:deno_os/30_os.js:124:10) at file:///$deno$stdin.mts:1:22 ``` The second example using `toObject` prints all environment variables: ``` [Object: null prototype] { ... AWS_SECRET_ACCESS_KEY: "my-secret-aws-key", ... } ``` Impact Software relying on the combination of both flags to allow access to most environment variables except a few sensitive ones will be vulnerable to malicious code trying to steal secrets using the Deno.env.toObject() method.

Related

Alias · CVE (1)

  • CVE-2025-48934 Deno is a JavaScript, TypeScript, and WebAssembly runtime. vulnerability

Weakness · CWE (1)

  • CWE-201 Insertion of Sensitive Information Into Sent Data weakness

References