T03 · Remote Payload Retrieval and Execution
- Location
SKILL.md:174- Finding
Unverified Remote Installer Is Piped Directly into a Shell
- Content
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Vulnerability Details
File Location:
SKILL.md:174
Vulnerability Type: Remote payload retrieval and execution
Risk Level: HighVulnerable Code Snippet:
markdown - Install: `curl -sSL https://api.free-ride.xyz/install.sh | sh`Technical Analysis
The installation command downloads a script from an external, mutable URL and immediately executes the response using
sh. The command does not pin a release, verify a cryptographic signature or checksum, save the script for inspection, or otherwise establish that the received content matches the version reviewed by the user.Because the project contains only
SKILL.md, the effective installer payload is not available for local audit. Control of the remote server, domain, TLS termination, deployment pipeline, or installer endpoint would permit an attacker to alter the commands executed after this Skill has been reviewed.The use of
curl -sSLalso suppresses routine output and follows redirects. No explicit integrity check is performed before execution. This behavior exceeds the minimum privileges necessary to provide installation guidance: documentation could instead direct users to a pinned, verifiable release artifact without granting mutable network content an immediate code-execution path.Attack Path
- A user or agent follows the installation instruction in
SKILL.md. curlrequestshttps://api.free-ride.xyz/install.shand follows any redirects.- The external endpoint, or infrastructure capable of changing its response, supplies an altered shell script.
- The pipe sends the response directly to
shwithout review or integrity validation. - The supplied commands execute with all permissions held by the invoking user.
- The payload can read or modify user-accessible files, collect credentials, install additional software, or establish persistence if the user's permissions allow it.
Impact Assessment
Successful exp ...[truncated 747 chars]
- A user or agent follows the installation instruction in
- Remediation
View remediation
Remediation Suggestions
-
Remove the direct
curl | shinstallation instruction. -
Publish versioned installer or release artifacts through a verifiable source.
-
Pin the documentation to a specific release version rather than a mutable endpoint.
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Publish a SHA-256 or stronger digest through an independently authenticated release channel, or sign artifacts with a documented signing key.
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Require users to download and verify the artifact before execution, for example:
bash curl --fail --show-error --location \ --output freeride-install.sh \ https://example.invalid/releases/vX.Y.Z/freeride-install.sh echo '<EXPECTED_SHA256> freeride-install.sh' | sha256sum --check - less freeride-install.sh sh freeride-install.sh -
Prefer installation through a reputable package manager with a pinned version and reproducible source.
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Include the installer source in the audited repository so filesystem changes, dependency installation, telemetry configuration, and persistence behavior can be reviewed.
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Ensure the installer follows least privilege, does not require elevated permissions unless strictly necessary, and clearly discloses every file and service it creates.
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