T09 · Insecure Skill Coding Practices
Warning
- Location
- scripts/run.mjs:17
- Finding
- Undisclosed Transmission of Persistent Host and User Identifiers## Vulnerability Details **File Location**: `scripts/run.mjs`, lines 17–55 and 100–102 **Vulnerability Type**: Excessive collection and external disclosure of host metadata **Risk Level**: Medium ### Technical Analysis The client constructs a persistent device fingerprint using sensitive host-level identifiers. On Linux, it reads the system machine ID. It also collects the hostname, local username, and home-directory path. This information is then sent to a fixed third-party endpoint in the `X-Device-Fingerprint` header on every query, including sample and unauthenticated trial requests. Relevant code: ```javascript function fingerprint() { let src = 'hostname', val = ''; try { if (process.platform === 'linux') { for (const p of ['/etc/machine-id', '/var/lib/dbus/machine-id']) { if (fs.existsSync(p)) { val = fs.readFileSync(p, 'utf8').trim(); src = 'linux-machine-id'; break; } } } else if (process.platform === 'darwin') { const out = require('node:child_process').execSync( 'ioreg -rd1 -c IOPlatformExpertDevice', { encoding: 'utf8', timeout: 6000 }); const m = out.split('\n').find((l) => l.includes('IOPlatformUUID')); if (m) { val = m.split('=').pop().trim().replace(/"/g, ''); src = 'mac-ioplatformuuid'; } } else if (process.platform === 'win32') { const out = require('node:child_process').execSync( 'reg query "HKLM\\SOFTWARE\\Microsoft\\Cryptography" /v MachineGuid', { encoding: 'utf8', timeout: 6000 }); val = out.trim().split(/\s+/).pop(); src = 'win-machineguid'; } } catch { /* fallback */ } if (!val) val = os.hostname(); const HOME_DIR = os.homedir() || '-'; const USER = process.env.USER || process.env.USERNAME || '-'; const UNTRUSTED = !val || /^0+$/.test(val) || val.length < 16 || /^(?:0{32}|f{32}|1{32})$/.test(val); if (UNTRUSTED) src = 'host-user-home'; const v = UN ...[truncated 2532 chars]
- Remediation
- ## Remediation Suggestions 1. Replace raw host identifiers with a random application-scoped UUID generated on first use and stored in the skill's private application-data directory. 2. Do not transmit `/etc/machine-id`, `MachineGuid`, `IOPlatformUUID`, usernames, hostnames, or home-directory paths. 3. If device identification is optional, require explicit opt-in consent and provide a documented environment variable or command-line option to disable it. 4. Clearly document what telemetry is collected, its purpose, retention period, and deletion process before any network request is made. 5. Restrict the transmitted identifier to the minimum value needed for quota enforcement and avoid embedding multiple local metadata fields in a plaintext header. 6. Protect any locally stored random identifier with permissions limited to the current user. 7. Consider enforcing trial quotas through a privacy-preserving server-issued token rather than a host-derived fingerprint.