@actions/core has Delimiter Injection Vulnerability in exportVariable
Date: 2022-08
Affected: npm/@actions/core
Attack vector: command-injection
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2022-35954
CWE: CWE-74
CWE-77
CVSS: 5 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N)

## Impact The `core.exportVariable` function uses a well known delimiter that attackers can use to break out of that specific variable and assign values to other arbitrary variables. Workflows that write untrusted values to the `GITHUB_ENV` file may cause the path or other environment variables to be modified without the intention of the workflow or action author. ## Patches Users should upgrade to `@actions/core v1.9.1`. ## Workarounds If you are unable to upgrade the `@actions/core` package, you can modify your action to ensure that any user input does not contain the delimiter `_GitHubActionsFileCommandDelimeter_` before calling `core.exportVariable`. ## References [More information about setting-an-environment-variable in workflows](https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#setting-an-environment-variable) If you have any questions or comments about this advisory: * Open an issue in [`actions/toolkit`](https://github.com/actions/toolkit/issues)


Mitigations:

Architectural layers (MAESTRO):