T05 · Unauthorized Access and Privilege Escalation
Warning
- Location
- SKILL.md:86
- Finding
- Excessive Google Drive OAuth Permissions## Vulnerability Details **File Location**: `SKILL.md:86-94`; duplicated in `excel-workflow-skill-package/SKILL.md:86-94` **Vulnerability Type**: Excessive OAuth scope and violation of least privilege **Risk Level**: Medium **Vulnerable Code Snippet**: ```bash # Configure rclone with Google Drive rclone config ``` ```text Follow prompts: - Name: `gdrive` - Storage: `drive` (Google Drive) - Scope: `1` (Full access) - Auto config: `y` (opens browser for OAuth) ``` ### Technical Analysis The documented workflow requires Google Drive synchronization for Excel files stored under `gdrive:Excel/`, but the setup instructions explicitly direct users to select OAuth scope `1`, described as full access. This grants rclone access beyond the dedicated Excel directory and beyond the minimum permissions necessary for the stated backup workflow. The OAuth token generated by this process is normally retained in the local rclone configuration. Any process or account capable of reading and using that token may consequently exercise the full permissions granted to rclone. Folder naming does not create an OAuth authorization boundary, so limiting normal operations to `gdrive:Excel/` does not prevent a stolen or misused token from accessing unrelated Drive content. ### Attack Path 1. A user follows the skill instructions and runs `rclone config`. 2. The user selects scope `1`, granting full Google Drive access. 3. rclone stores the resulting OAuth credentials in its local configuration. 4. An attacker who compromises the host, gains access to the relevant user account, or obtains the rclone configuration extracts the token. 5. The attacker configures rclone or another compatible OAuth client with the token. 6. The attacker reads, modifies, uploads, moves, or deletes files outside the intended `Excel/` directory, subject to the privileges granted by Google Drive. ### Impact Assessment Successful exploitation can expose th ...[truncated 344 chars]
- Remediation
- ## Remediation Suggestions 1. Select the narrowest rclone-supported Google Drive scope that satisfies the workflow, preferably one limited to files created by the application. 2. Use a dedicated Google account or isolated Shared Drive containing only workflow data if a sufficiently narrow folder-level OAuth scope is unavailable. 3. Avoid recommending full Drive access as the default. If it is unavoidable, clearly describe the security implications and require explicit user confirmation. 4. Protect the rclone configuration with restrictive filesystem permissions and ensure it is not included in backups, logs, repositories, or support bundles. 5. Document how users can inspect authorized applications, revoke the OAuth grant, and rotate credentials after suspected compromise. 6. Apply the same changes to both copies of `SKILL.md` to prevent the insecure setup instructions from remaining in the packaged duplicate.