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Actions Core Delimiter Injection Vulnerability

Published Fri, Aug 12th, 2022

Platforms

github

Summary

The @actions/core package had a delimiter injection vulnerability in the exportVariable function. Attackers could use a known delimiter to break out of a specific variable and assign values to other arbitrary variables. This may have allowed modification of path or environment variables without the intention of workflow or action authors.

Affected Services

GitHub Actions

Remediation

Upgrade to @actions/core v1.9.1 or ensure user input does not contain the delimiter '_GitHubActionsFileCommandDelimeter_' before calling core.exportVariable.

Tracked CVEs

CVE-2022-35954

References

Contributed by https://github.com/sshayb

Entry Status

Finalized

Disclosure Date

-

Exploitability Period

Until 2022/08/12

Known ITW Exploitation

-

Detection Methods

Review workflows and actions that write untrusted values to the GITHUB_ENV file. Check for potential manipulation of path or other environment variables.

Piercing Index Rating

-

Discovered by

Juho Nurminen