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Cloudflare API Token

Cloudflare API Tokens are credentials used to authenticate and authorize access to Cloudflare's suite of services, including DNS management, security settings, and content delivery network configurations. These tokens are critical for automating tasks and integrating Cloudflare services with other applications. Exposure of an API token can lead to unauthorized access to your Cloudflare account, potentially allowing attackers to manipulate DNS records, alter security settings, or disrupt service availability.

How Does It Look​

Cloudflare API Tokens can appear in various contexts, such as:

  • Environment variables:

    export CLOUDFLARE_API_TOKEN="cf1234567890abcdef1234567890abcdef123456"

  • Configuration files (JSON):

    {
      "cloudflare": {
        "apiToken": "cf1234567890abcdef1234567890abcdef123456"
      }
    }

  • Code snippets:

    import requests

    headers = {
        "Authorization": "Bearer cf1234567890abcdef1234567890abcdef123456"
    }
    response = requests.get("https://api.cloudflare.com/client/v4/zones", headers=headers)

  • Connection strings:

    cloudflare://api.cloudflare.com?token=cf1234567890abcdef1234567890abcdef123456

Severity​

  • 🔴 Critical

The severity of a Cloudflare API Token exposure is critical because it can provide full access to manage DNS records, security settings, and other configurations. The blast radius includes potential service disruptions, data exposure, and unauthorized changes to web properties.

What Can an Attacker Do?​

With immediate access to a Cloudflare API Token, an attacker can perform a range of malicious activities:

  • Modify DNS records (if the token has DNS edit permissions), potentially redirecting traffic to malicious sites.
  • Alter security settings (if the token has security permissions), weakening defenses against attacks.
  • Access sensitive data (if the token has read permissions), such as logs and analytics.
  • Disrupt services by changing configurations or disabling features (if the token has appropriate permissions).

An attacker could also escalate their access by using the token to gather information about the account and potentially exploit other vulnerabilities or misconfigurations.

Real-World Impact​

The exposure of a Cloudflare API Token poses significant business risks, including:

  • Data Exposure: Unauthorized access to DNS records and security settings (if the token has read access).
  • Financial Loss: Costs associated with service disruptions and potential legal liabilities (if billing/resource creation is permitted).
  • Operational Disruption: Downtime or degraded performance due to unauthorized configuration changes (if the attacker has modify permissions).
  • Reputational Damage: Loss of customer trust and brand integrity due to security breaches.

In worst-case scenarios, attackers could leverage the token to launch further attacks on connected systems, amplifying the impact.

Prerequisites for Exploitation​

To exploit a Cloudflare API Token, an attacker needs:

  • Network access to the Cloudflare API endpoints.
  • Additional context such as account IDs or specific zone identifiers.
  • No rate limits or IP restrictions that could hinder unauthorized access.

How to Verify If It's Active​

To verify if a Cloudflare API Token is active, use the following command:

curl -X GET "https://api.cloudflare.com/client/v4/user/tokens/verify" \
     -H "Authorization: Bearer [TOKEN]" \
     -H "Content-Type: application/json"

Valid credential response: A successful response will include a status of "active" and details about the token's permissions.

Invalid/expired credential response: An error message indicating invalid credentials or token expiration.

Detection Patterns​

Common Variable Names:

  • CLOUDFLARE_API_TOKEN
  • CF_API_TOKEN
  • CLOUDFLARE_TOKEN
  • CF_TOKEN
  • API_TOKEN
  • TOKEN

File Locations:

  • .env
  • config.json
  • settings.yaml
  • cloudflare-config.js
  • credentials.txt

Regex Pattern:

cf[a-zA-Z0-9]{30,40}

Remediation Steps​

  1. Revoke immediately - Go to Cloudflare Dashboard > API Tokens and delete the compromised token.
  2. Audit access logs - Review Cloudflare audit logs for unauthorized changes or access during the exposure window.
  3. Assess blast radius - Identify all systems, applications, and environments that used the exposed token.
  4. Rotate credential - Create a new API token in Cloudflare with least-privilege permissions.
  5. Update dependent systems - Deploy the new token to all applications and update CI/CD pipelines securely.
  6. Harden access controls - Enable IP allowlisting in Cloudflare and require two-factor authentication for account access.
  7. Implement secrets management - Migrate credentials to a secrets manager (HashiCorp Vault, AWS Secrets Manager) to prevent hardcoding.
  8. Add detection controls - Set up pre-commit hooks and repository scanning to catch credential leaks before they reach production.

Credential exposures often go undetected for extended periods, increasing the window for exploitation. As a long-term strategy, plan to establish an internal process or engage an external vendor for continuous external exposure monitoring. This helps identify leaked secrets across public repositories, paste sites, dark web forums, and other external sources before attackers can leverage them. Proactive detection and rapid response are essential to minimizing the impact of credential leaks.

References​