EUVD-2025-20825

Comprehensive Technical Analysis of EUVD-2025-20825

1. Vulnerability Assessment and Severity Evaluation

Vulnerability Description: The vulnerability in Folo, identified as EUVD-2025-20825, involves the misuse of the pull_request_target event in the GitHub Actions workflow file .github/workflows/auto-fix-lint-format-commit.yml. This misconfiguration allows untrusted code execution with full access to repository secrets, including the GITHUB_TOKEN.

Severity Evaluation: The CVSS (Common Vulnerability Scoring System) base score of 9.1 indicates a critical vulnerability. The vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N breaks down as follows:

• AV:N (Network): The vulnerability is exploitable over the network.
• AC:L (Low): The attack complexity is low.
• PR:N (None): No privileges are required to exploit the vulnerability.
• UI:N (None): No user interaction is required.
• S:U (Unchanged): The scope is unchanged.
• C:H (High): Confidentiality impact is high.
• I:H (High): Integrity impact is high.
• A:N (None): Availability impact is none.

This high severity is due to the potential for complete repository takeover and exfiltration of sensitive data.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

• Untrusted Code Execution: An attacker can submit a pull request with malicious code that exploits the pull_request_target event to execute arbitrary commands.
• Secret Exfiltration: The malicious code can access and exfiltrate secrets, including the GITHUB_TOKEN, which has high privileges.

Exploitation Methods:

• Pull Request Submission: An attacker submits a pull request with a crafted payload in the .github/workflows/auto-fix-lint-format-commit.yml file.
• Command Execution: The malicious code in the pull request executes commands that access and exfiltrate secrets.
• Repository Takeover: Using the exfiltrated GITHUB_TOKEN, the attacker can perform actions such as modifying repository contents, deleting branches, and adding malicious collaborators.

3. Affected Systems and Software Versions

Affected Systems:

• Folo: The vulnerability affects versions of Folo prior to the commit 585c6a591440cd39f92374230ac5d65d7dd23d6a.

Software Versions:

• Folo: All versions before the fix commit 585c6a591440cd39f92374230ac5d65d7dd23d6a.

4. Recommended Mitigation Strategies

Immediate Actions:

• Update to the Latest Version: Ensure that all instances of Folo are updated to the version that includes the fix commit 585c6a591440cd39f92374230ac5d65d7dd23d6a.
• Review Pull Requests: Implement a strict review process for pull requests, especially those that modify workflow files.
• Limit Secrets Access: Restrict the use of high-privilege secrets like GITHUB_TOKEN and ensure they are only accessible to trusted workflows.

Long-Term Strategies:

• Code Review Policies: Enforce rigorous code review policies for any changes to GitHub Actions workflows.
• Security Audits: Conduct regular security audits of GitHub Actions workflows to identify and mitigate potential vulnerabilities.
• Least Privilege Principle: Apply the principle of least privilege to all secrets and workflows to minimize the impact of any potential exploits.

5. Impact on European Cybersecurity Landscape

Regulatory Compliance:

• GDPR: The exfiltration of sensitive data could result in GDPR violations, leading to significant fines and legal consequences.
• NIS Directive: Organizations subject to the NIS Directive must ensure the security of their digital infrastructure, and this vulnerability could compromise their compliance status.

Economic Impact:

• Reputation Damage: Organizations using Folo could suffer reputational damage if their repositories are compromised.
• Operational Disruption: The takeover of repositories could lead to operational disruptions, affecting business continuity.

Cybersecurity Ecosystem:

• Supply Chain Risks: The vulnerability highlights the risks associated with third-party dependencies and the need for robust supply chain security measures.
• Collaborative Efforts: Encourages collaboration between vendors, researchers, and regulatory bodies to identify and mitigate similar vulnerabilities.

6. Technical Details for Security Professionals

Workflow Configuration:

• Misconfigured Event: The pull_request_target event in the .github/workflows/auto-fix-lint-format-commit.yml file allows untrusted code execution.
• Secrets Access: The workflow has access to secrets, including the GITHUB_TOKEN, which has high privileges.

Exploitation Steps:

1. Craft Malicious Payload: Create a pull request with a malicious payload that exploits the pull_request_target event.
2. Submit Pull Request: Submit the pull request to the target repository.
3. Execute Malicious Code: The malicious code executes, accessing and exfiltrating secrets.
4. Repository Takeover: Use the exfiltrated GITHUB_TOKEN to perform unauthorized actions on the repository.

Detection and Response:

• Monitoring: Implement monitoring for unusual activities in GitHub Actions workflows and repository changes.
• Incident Response: Develop an incident response plan to quickly identify and mitigate any exploitation attempts.
• Logging: Enable detailed logging for GitHub Actions workflows to facilitate forensic analysis in case of an incident.

By addressing these points, organizations can effectively mitigate the risks associated with EUVD-2025-20825 and enhance their overall cybersecurity posture.