Affected: brightio penelope

Penelope Shell Handler is a post-exploitation shell handler for authorized security testing. Prior to 0.20.0, the Unix download() implementation in penelope.py used tar.extractall(local_download_folder) on tar archives returned by remote sessions without validating member paths, allowing a malicious or compromised session to write files outside the intended download directory and potentially overwrite ~/.penelope/peneloperc. This issue is fixed in version 0.20.0.

Affected: PyPI: penelope-shell-handler

### Summary

Penelope versions prior to 0.19.3 extracted tar archives received from remote sessions without validating archive member paths. When using the affected Unix download path, a malicious or compromised remote session could return a crafted tar archive containing path traversal entries, such as `../`, causing files to be written outside the intended download directory on the Penelope operator's machine.

The impact is limited to files writable by the user running Penelope. In some cases, this arbitrary file write could be chained to operator-side code execution if the attacker can overwrite a file that Penelope or the user later executes, such as `~/.penelope/peneloperc`. The issue has been fixed in version 0.19.3 by rejecting unsafe archive paths during extraction.

### Affected conditions

The issue requires the operator to use the Main Menu `download` command to download files from a malicious or compromised remote session that can influence the tar archive returned to Penelope. The Python agent download path is not affected in the same way because it does not rely on the remote `tar` command.

The vulnerable behavior is related to Python's historical `tarfile` extraction defaults. In Python versions before 3.14, `TarFile.extractall()` did not use the safer `data` extraction filter by default, so applications extracting untrusted tar archives needed to explicitly provide a safe extraction filter or perform their own path validation.

Python 3.14 changes the defau…