Affected: langroid

Langroid is a framework for building large-language-model-powered applications. Prior to version 0.64.0, Langroid's `ReadFileTool` and `WriteFileTool` appear to treat `curr_dir` as the intended working-directory boundary for file operations. However, the tools only change the process working directory to `curr_dir` and then operate on the user-supplied `file_path` without resolving and enforcing that the final path remains inside `curr_dir`. As a result, a tool caller can supply path traversal sequences such as `../secret.txt` to read files outside the configured current directory, or `../written_by_tool.txt` to write files outside that directory. This can impact applications that expose Langroid file tools to an LLM agent, user-controlled tool call, or delegated coding/documentation agent while relying on `curr_dir` to restrict file access to a project/workspace directory. Version 0.64.0 patches the issue.

Affected: PyPI: langroid

### Summary

Langroid's `ReadFileTool` and `WriteFileTool` appear to treat `curr_dir` as the intended working-directory boundary for file operations. However, the tools only change the process working directory to `curr_dir` and then operate on the user-supplied `file_path` without resolving and enforcing that the final path remains inside `curr_dir`.

As a result, a tool caller can supply path traversal sequences such as `../secret.txt` to read files outside the configured current directory, or `../written_by_tool.txt` to write files outside that directory.

This can impact applications that expose Langroid file tools to an LLM agent, user-controlled tool call, or delegated coding/documentation agent while relying on `curr_dir` to restrict file access to a project/workspace directory.

### Details

Affected components:

- `langroid/agent/tools/file_tools.py` - `langroid/utils/system.py`

Relevant behavior observed:

`ReadFileTool` contains a comment indicating the intended assumption:

```text # ASSUME: file_path should be relative to the curr_dir

The tool then changes into the configured current directory and calls read_file(self.file_path).

WriteFileTool similarly resolves curr_dir, changes into that directory, and calls create_file(self.file_path, self.content).

The issue is that changing the process working directory does not prevent traversal. A path such as ../secret.txt is still valid and resolves outside the configured curr_dir.

In local testing, ReadFileTool su…