T09 · Insecure Skill Coding Practices
Error
- Location
- scripts/crypto_lens.py:32
- Finding
- Hardcoded SkillPay API Credential Exposed in Distributed Source Code## Vulnerability Details **File Location**: `scripts/crypto_lens.py:32-34` **Vulnerability Type**: Hardcoded API credential **Risk Level**: High ### Vulnerable Code ```python BILLING_URL = "https://skillpay.me/api/v1/billing" BILLING_API_KEY = "sk_fbda2cd31455722ee28f08aebbf77af5f0002f21d1832f1b2102b756e20f2981" SKILL_ID = "73d7f580-817c-4df2-a0fb-0572f93e4b97" ``` The credential is subsequently transmitted as an authentication header: ```python data = _post_json( f"{BILLING_URL}/charge", {"user_id": user_id, "skill_id": SKILL_ID}, headers={"X-API-Key": BILLING_API_KEY}, ) ``` ### Technical Analysis The Skill embeds a live-looking SkillPay API key directly in a client-side Python file. Any user who downloads, installs, or otherwise obtains the Skill package can extract and reuse this credential independently of the intended program. Although `SKILL.md` claims that the key can only initiate charges and cannot withdraw funds, this restriction is enforced externally by SkillPay and cannot be verified from the audited source. A static credential distributed to every client also cannot reliably distinguish legitimate Skill requests from requests made by an attacker. The billing request contains a caller-controlled `user_id` and a fixed `skill_id`. The request does not bind the API credential to a particular installation, invocation, command, or expected price. The actual price is controlled by the remote SkillPay configuration rather than included and validated by the client. ### Attack Path 1. An attacker downloads or reads the Skill package. 2. The attacker extracts `BILLING_API_KEY`, `SKILL_ID`, and the billing endpoint from `scripts/crypto_lens.py`. 3. The attacker constructs requests to `https://skillpay.me/api/v1/billing/charge`. 4. The attacker supplies the exposed key in the `X-API-Key` header and submits chosen billing identifiers in the JSON request body. 5. If the remote service do ...[truncated 1282 chars]
- Remediation
- ## Remediation Suggestions 1. Revoke and rotate the exposed API key because it must be treated as compromised once distributed. 2. Remove long-lived billing credentials from all client-side source code and package history. 3. Route billing through a publisher-controlled server that stores the credential in a secrets manager or protected environment variable. 4. Issue short-lived, narrowly scoped invocation tokens instead of distributing a reusable publisher credential. 5. Bind each authorized billing operation to the user identity, Skill ID, command, exact amount, expiration time, and a unique nonce. 6. Require the client to display and validate the exact charge amount returned by the billing service before performing the paid operation. 7. Add replay protection, per-user and per-key rate limits, anomaly detection, and auditable request identifiers. 8. Avoid relying on documentation claims about key permissions; enforce least privilege through the billing provider's server-side policy. 9. Establish an automated credential-rotation and incident-response process.