Skip to main content
VulnerabilityPublished

openstackclient · setuptools: Windows path escape via namespace_packages.txt during legacy wheel installation Description

Affects openstackclientSource GCVE Database

0

CVSS 1.0 Low : upgrade to 10.5.0 when convenient.

Data as of 26 Oct 2026, 17:12 UTC

CVSS 4.0 base score
1.0Low
How severe the flaw is on the 0–10 CVSS scale.
Patch
Available – fixed in 10.5.0
CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:A/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N

What to do

Upgrade openstackclient to 10.5.0.

Affected software

ProductAffectedFixed in
Homebrewopenstackclientpkg:brew/openstackclientOther threatsAffected
  • >=6.6.1 <10.5.0
Fixed in
  • 10.5.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

### Summary On Windows, attacker-controlled content in a wheel's `.dist-info/namespace_packages.txt` can cause setuptools' legacy wheel installation path to create an `__init__.py` outside the requested `destination_eggdir`. The attacker can influence the destination path, but not the contents of the created file. ### Details Tested setuptools commit: `6ead555c5fb29bc57fe6105b1bffc163f56fd558` Relevant source: `setuptools/wheel.py` SHA-256: `359b7e0d5dd8c3135653abe08a8ed5dc0352eadfd7df22cb5e2b5303b7c3cafd` The relevant call path is: `Wheel(wheel_path).install_as_egg(destination)` → `_install_as_egg` → `_convert_metadata` → `_fix_namespace_packages` A wheel can provide attacker-controlled content in: `<distribution>.dist-info/namespace_packages.txt` The namespace value is eventually used approximately as: ```python mod_dir = os.path.join(destination_eggdir, *mod.split('.')) mod_init = os.path.join(mod_dir, '__init__.py') If mod is a Windows drive-qualified absolute path containing no dots, mod.split('.') preserves it as a single component. On Windows, os.path.join(destination_eggdir, absolute_component) discards the original base directory and resolves to the attacker-supplied absolute path. The existing wheel filename and ZIP traversal checks do not validate this metadata value before it is subsequently interpreted as a filesystem path. ```markdown ### PoC The reproduction was performed entirely inside a disposable temporary directory. Layout: ```text sandbox/ destination/ outside/ input/ canary.txt ``` A synthetic wheel was created containing: `demo_pkg-1.0.dist-info/namespace_packages.txt` whose content was the absolute path of: `sandbox\outside` The real acquired setuptools implementation was then invoked: ```python setuptools.wheel.Wheel(synthetic_wheel).install_as_egg( sandbox_destination ) ``` The operation completed without exception. Expected metadata was created under: `sandbox\destination\EGG-INFO` but setuptools also created: `sandbox\outside\__init__.py` The file did not exist before execution. Its contents were: ```python __import__('pkg_resources').declare_namespace(__name__) ``` The unrelated canary remained byte-identical. The sandbox was deleted after recording the evidence. ``` ### Impact A crafted wheel can cause setuptools to create a fixed-content `__init__.py` outside the intended installation directory at a filesystem path influenced by the wheel, with the permissions of the process performing the installation. The demonstrated reproduction required the target parent directory to already exist.

References

Community reviews

Loading reviews…