title: Delimiter injection vulnerability in @actions/core exportVariable
description: 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`.
problem types: CWE-77: Improper Neutralization of Special Elements used in a Command ('Command Injection')
affected:
{
product: toolkit
vendor: actions
versions:
status: affected, version: <= 1.9.0
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: NONE
baseScore: 5
baseSeverity: MEDIUM
confidentialityImpact: NONE
integrityImpact: LOW
privilegesRequired: LOW
scope: CHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N
version: 3.1
]