Langroid: Path traversal in the file tools allows read/write outside configured current directory

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.