Headline
CVE-2022-35954: Delimiter injection vulnerability in @actions/core exportVariable
The GitHub Actions ToolKit provides a set of packages to make creating actions easier. 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. Users should upgrade to @actions/core v1.9.1. 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.
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
If you have any questions or comments about this advisory:
- Open an issue in actions/toolkit
Related news
## 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...