T03 · Remote Payload Retrieval and Execution
Error
- Location
- SKILL.md:19
- Finding
- Unpinned Remote Source Is Downloaded, Compiled, and Executed## Vulnerability Details **File Location**: `SKILL.md`, lines 19-22 **Vulnerability Type**: Remote payload retrieval and execution **Risk Level**: Critical ```bash # On the target machine (Pi, VPS, any Linux box): curl -fsSL https://raw.githubusercontent.com/Awis13/seed/main/seeds/linux/seed.c -o seed.c gcc -O2 -o seed seed.c ./seed 8080 ``` ### Technical Analysis The deployment instructions retrieve C source from the mutable `main` branch of an external personal repository, compile it into a native executable, and run it without any source review, immutable version pinning, checksum validation, or signature verification. Because the effective source can change after this Skill has been reviewed, the audited package does not determine the code ultimately executed on the target. Compromise of the upstream repository, its maintainer account, the referenced branch, or the delivery infrastructure could substitute arbitrary native code. The supplied `curl` options validate HTTPS transport but do not establish that the retrieved source is an expected, reviewed version. This is principally remote payload retrieval and execution. It also creates a supply-chain risk through reliance on an unpinned and unverified external component. ### Attack Path 1. An attacker compromises the upstream repository or an account authorized to modify its `main` branch. 2. The attacker replaces `seeds/linux/seed.c` with malicious or backdoored C source. 3. A user or Agent follows the documented deployment instructions. 4. `curl` downloads the attacker-controlled source without verifying an immutable version or expected digest. 5. `gcc` compiles the source into a native executable. 6. `./seed 8080` executes the payload with the privileges of the user performing deployment. 7. The payload can access resources available to that account and may expose further remote-control functionality. ### Impact Assessment Successful exploitation provid ...[truncated 461 chars]
- Remediation
- ## Remediation Suggestions - Vendor the reviewed source into the Skill package so the audited artifact contains the exact code that will execute. - If remote retrieval is necessary, reference an immutable commit rather than `main`. - Publish and verify a cryptographic SHA-256 or stronger digest before compilation. - Prefer a signed release artifact and verify its signature against a pinned, independently distributed public key. - Stop deployment immediately if verification fails; never fall back to executing an unverified payload. - Present the source or a verified diff for review before compilation. - Compile and initially execute the service in an isolated, unprivileged environment with minimal filesystem, device, and network access. - Document the expected commit, digest, signer, and update procedure in `SKILL.md`.
