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Improper Input Validation


Severity High
Score 7.8/10


The package pdm is a Python package and dependency manager supporting the latest PEP standards. It's possible to craft a malicious `pdm.lock` file in versions through 2.9.3 that could allow e.g. an insider or a malicious open source project to appear to depend on a trusted PyPI project but actually install another project. A project `foo` can be targeted by creating the project `foo-2` and uploading the file `foo-2-2.tar.gz` to PyPI will see this as project `foo-2` version `2`, while PDM will see this as project `foo` version `2-2`. The version must only be `parseable as a version` and the filename must be a prefix of the project name, but it's not verified to match the version being installed. Version `2-2` is also not a valid normalized version per PEP 440. Matching the project name exactly (not just prefix) would fix the issue. When installing dependencies with PDM, what's actually installed could differ from what's listed in `pyproject.toml` (including arbitrary code execution on install). It could also be used for downgrade attacks by only changing the version. Users are advised to upgrade. There are no known workarounds for this vulnerability. This issue also affects the package unearth versions prior to 0.11.2.

  • LOW
  • HIGH
  • NONE
  • HIGH
  • HIGH

CWE-20 - Improper Input Validation

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

Advisory Timeline

  • Published