The Agent Skills Directory

[DYNAMIC_EXECUTION]: The skill provides examples of sourcing external configuration files using a variable path (e.g., source "${CONFIG_FILE}" in examples/advanced-script.sh and references/common-patterns.md). This pattern allows for the execution of arbitrary shell code contained within the sourced file.
[COMMAND_EXECUTION]: In examples/advanced-script.sh, an unquoted here-document (<<EOF) is used to incorporate file content (line 208). Because the here-doc delimiter is not quoted, the shell will perform command substitution and variable expansion on the content of the input file ($(cat "${input_file}")) during execution. This could lead to arbitrary command execution if the script processes a file containing malicious shell sequences.
[EXTERNAL_DOWNLOADS]: The examples/library-example.sh file includes a utility function lib::download_file that uses curl to download content from a remote URL. While the function includes URL validation and optional checksum verification, it facilitates fetching external data into the agent's environment.
[INDIRECT_PROMPT_INJECTION]: The skill defines patterns for scripts that ingest and process external data (e.g., reading file contents in advanced-script.sh and basic-script.sh). This establishes an attack surface where malicious instructions embedded in processed files could attempt to influence the agent's behavior.
Ingestion points: examples/advanced-script.sh (processes files in INPUT_FILES array), examples/basic-script.sh (reads input_file).
Boundary markers: The provided script templates do not implement specific delimiters or instructions for the agent to ignore potentially malicious embedded content within the processed data.
Capability inventory: The included scripts demonstrate capabilities for file system operations (rm, cp, mkdir), network access (curl), and dynamic execution (source).
Sanitization: The skill provides utility functions in examples/library-example.sh for URL validation and checksum verification to mitigate download risks, but does not provide specific sanitization for data processed within the shell scripts themselves.

bash-shell