CVE-2025-48934 – deno

Package

Manager: cargo
Name: deno
Vulnerable Version: >=0 <2.1.13 || >=2.2.0 <2.2.13

Severity

Level: Medium

CVSS v3.1: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:P

EPSS: 0.0006 pctl0.1901

Details

Deno.env.toObject() ignores the variables listed in --deny-env and returns all environment variables ### Summary The [Deno.env.toObject](https://docs.deno.com/api/deno/~/Deno.Env.toObject) method ignores any variables listed in the `--deny-env` option of the `deno run` command. When looking at the [documentation](https://docs.deno.com/runtime/fundamentals/security/#environment-variables) 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.

Metadata

Created: 2025-06-04T21:18:18Z
Modified: 2025-07-02T18:31:08Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/06/GHSA-7w8p-chxq-2789/GHSA-7w8p-chxq-2789.json
CWE IDs: ["CWE-201"]
Alternative ID: GHSA-7w8p-chxq-2789
Finding: F037
Auto approve: 1