T03 · Remote Payload Retrieval and Execution
Error
- Location
- references/setup.md:44
- Finding
- Mutable Remote Installation Script Is Executed Directly Through a Shell<![CDATA[ ## Vulnerability Details **File Location**: `references/setup.md:44-49` **Vulnerability Type**: Remote payload retrieval and execution **Risk Level**: High ### Vulnerable Code ```bash # Install Auth0 CLI if ! command -v auth0 &> /dev/null; then [[ "$OSTYPE" == "darwin"* ]] && brew install auth0/auth0-cli/auth0 || \ curl -sSfL https://raw.githubusercontent.com/auth0/auth0-cli/main/install.sh | sh -s -- -b /usr/local/bin fi ``` ### Technical Analysis The setup guide downloads `install.sh` from the mutable `main` branch of an external GitHub repository and immediately pipes it into `sh`. The downloaded content is neither displayed for review nor verified against a pinned cryptographic checksum or signature. Although the URL belongs to the official Auth0 GitHub organization, using a mutable branch means that the effective code executed by the Skill can change after the Skill itself has been reviewed. Compromise of the upstream repository, maintainer account, release process, or delivery channel could therefore turn this installation command into arbitrary shell execution. The command also requests installation into `/usr/local/bin`, which is a system-wide executable directory. This exceeds the minimum privileges required to document or configure a Flask integration. If the setup is run by a privileged agent or inside a root container, the remote script can modify system files with the agent's full privileges. This is a supply-chain execution weakness rather than evidence that the current Auth0 script is intentionally malicious. ### Attack Path 1. An attacker compromises the upstream repository, a maintainer account, or another component capable of changing the contents returned for `main/install.sh`. 2. The attacker inserts arbitrary commands into the remote installation script. 3. A user or agent follows the automated setup instructions on a system without the `auth0` command. 4. `curl` retrieves the attacker-controlled content. 5. The conten ...[truncated 966 chars]
- Remediation
- <![CDATA[ ## Remediation Suggestions 1. Do not pipe remote content directly into a shell. 2. Prefer a trusted package manager or a versioned official release package. 3. Pin the installer or binary to an immutable release version or commit rather than `main`. 4. Download the artifact separately and verify a publisher-provided SHA-256 checksum or cryptographic signature before execution. 5. Present the exact command and source to the user and obtain explicit confirmation before installing software. 6. Install into a user-owned directory such as `$HOME/.local/bin` unless system-wide installation is explicitly required. 7. Avoid automatically invoking privileged installation paths from an agent-driven setup. 8. A safer pattern is: ```bash VERSION="<pinned-version>" INSTALLER="$(mktemp)" curl --proto '=https' --tlsv1.2 -fL \ "https://raw.githubusercontent.com/auth0/auth0-cli/<immutable-commit>/install.sh" \ -o "$INSTALLER" printf '%s %s\n' "<publisher-verified-sha256>" "$INSTALLER" | sha256sum -c - less "$INSTALLER" sh "$INSTALLER" -b "$HOME/.local/bin" rm -f "$INSTALLER" ``` The checksum must come from an independently authenticated, publisher-controlled release channel. ]]>
