CVE-2024-8156 is a command injection vulnerability classified under CWE-77, found in the GitHub Actions workflow file (workflow-checker.yml) of the significant-gravitas/autogpt project. The vulnerability stems from the insecure use of the GitHub Actions context variable `github.head.ref`, which represents the branch name of a pull request. Since this input is controlled by an external user (the pull request creator), it can be manipulated to include malicious shell commands. When the workflow executes, these commands run with the permissions of the GitHub Actions runner, potentially allowing an attacker to execute arbitrary commands on the CI infrastructure. This can lead to severe consequences such as reverse shell access, enabling persistent access to the environment, and exfiltration of sensitive information like tokens and keys used in the workflow. The vulnerability affects all versions of the project up to and including the latest release, with no patch currently available. The CVSS v3.0 score is 8.8 (high severity), reflecting network attack vector, low attack complexity, no privileges required, user interaction required (opening a pull request), and high impact on confidentiality, integrity, and availability. Although no known exploits have been reported in the wild, the vulnerability's nature and ease of exploitation make it a critical concern for any organization using this project in their CI/CD pipelines.

For European organizations, the impact of this vulnerability can be significant, especially those integrating significant-gravitas/autogpt into their development and deployment workflows. Exploitation could lead to unauthorized command execution within CI environments, resulting in compromise of build infrastructure, leakage of sensitive credentials (such as API keys, tokens, or secrets stored in GitHub Actions), and potential lateral movement into internal networks. This could disrupt software delivery pipelines, cause data breaches, and damage organizational reputation. Organizations in sectors with stringent data protection regulations (e.g., GDPR) face additional compliance risks and potential fines if sensitive data is exposed. The risk is amplified for organizations that rely heavily on automated workflows and open collaboration models where external contributors can submit pull requests. The vulnerability also poses a risk to supply chain security, as compromised CI environments can lead to the injection of malicious code into software releases.

Immediate mitigation steps include disabling or restricting the affected GitHub Actions workflow (workflow-checker.yml) until a secure patch or update is available. Organizations should implement strict validation and sanitization of all untrusted inputs used in workflows, especially branch names and other user-controlled variables. Using GitHub Actions built-in functions or third-party actions that safely handle inputs can reduce risk. Limit the permissions of GitHub Actions runners by adopting the principle of least privilege, including restricting access to secrets and tokens. Employ branch protection rules and require trusted reviewers for pull requests to reduce the risk of malicious branches being merged or triggering workflows. Monitor CI logs and workflow runs for suspicious activity indicative of exploitation attempts. Additionally, consider isolating CI environments and using ephemeral runners to limit persistence of any compromise. Organizations should track updates from the significant-gravitas/autogpt project for official patches and apply them promptly once available.