CVE-2025-53546

Comprehensive Technical Analysis of CVE-2025-53546

1. Vulnerability Assessment and Severity Evaluation

CVE ID: CVE-2025-53546 CVSS Score: 9.1

The vulnerability in question affects the Folo application, which organizes feeds content into a single timeline. The issue arises from the use of pull_request_target in the GitHub Actions workflow file .github/workflows/auto-fix-lint-format-commit.yml. This configuration allows untrusted code to execute with full access to secrets from the base repository, including the GITHUB_TOKEN.

Severity Evaluation:

• CVSS Score: 9.1 (Critical)
• Impact: High
• Exploitability: High

The high CVSS score indicates a critical vulnerability that can lead to significant security risks if exploited. The ability to exfiltrate the GITHUB_TOKEN, which has high privileges, makes this vulnerability particularly dangerous.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

1. Untrusted Code Execution: An attacker can submit a pull request with malicious code that exploits the pull_request_target configuration to execute untrusted code.
2. Secret Exfiltration: The malicious code can access and exfiltrate secrets, including the GITHUB_TOKEN, which has content write privileges.
3. Repository Takeover: With the GITHUB_TOKEN, an attacker can perform actions such as modifying code, creating new branches, and even deleting the repository.

Exploitation Methods:

• Pull Request Submission: An attacker submits a pull request with malicious code designed to exploit the pull_request_target configuration.
• Code Execution: The malicious code executes within the GitHub Actions workflow, gaining access to secrets.
• Token Exfiltration: The attacker exfiltrates the GITHUB_TOKEN and uses it to perform unauthorized actions within the repository.

3. Affected Systems and Software Versions

Affected Systems:

• GitHub repositories using the Folo application with the vulnerable GitHub Actions workflow configuration.

Software Versions:

• The vulnerability is present in versions of Folo prior to the commit 585c6a591440cd39f92374230ac5d65d7dd23d6a.

4. Recommended Mitigation Strategies

1. Update Workflow Configuration:

   • Ensure that the pull_request_target configuration is not used in the .github/workflows/auto-fix-lint-format-commit.yml file.
   • Use pull_request instead of pull_request_target to limit the scope of code execution.

2. Review and Audit Pull Requests:

   • Implement strict review processes for pull requests to ensure that no malicious code is merged.
   • Use automated tools to scan pull requests for potential security issues.

3. Limit Token Permissions:

   • Reduce the permissions of the GITHUB_TOKEN to the minimum required for the workflow to function.
   • Use personal access tokens (PATs) with limited scope for sensitive operations.

4. Monitor and Log Actions:

   • Enable logging and monitoring for GitHub Actions to detect and respond to suspicious activities.
   • Regularly review logs for any unauthorized access or actions.

5. Impact on Cybersecurity Landscape

The discovery and exploitation of this vulnerability highlight the importance of securing CI/CD pipelines and managing secrets effectively. The ability to exfiltrate high-privilege tokens and take over repositories underscores the need for robust security practices in DevOps environments. Organizations must prioritize the security of their CI/CD workflows to prevent such critical vulnerabilities from being exploited.

6. Technical Details for Security Professionals

Vulnerable Workflow Configuration:

name: Auto Fix Lint Format Commit
on:
  pull_request_target:
    types: [opened, synchronize]
jobs:
  auto-fix:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - name: Run lint and format
        run: |
          # Malicious code can be executed here

Fixed Workflow Configuration:

name: Auto Fix Lint Format Commit
on:
  pull_request:
    types: [opened, synchronize]
jobs:
  auto-fix:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - name: Run lint and format
        run: |
          # Safe code execution

References:

• GitHub Commit Fixing the Vulnerability
• GitHub Security Advisory

By addressing this vulnerability and implementing the recommended mitigation strategies, organizations can significantly reduce the risk of unauthorized access and repository takeover.