rattler_cache and py-rattler handle package metadata from conda channels by using the package record's build string as part of a cache key that forms a filesystem path. If a malicious or untrusted channel publishes repodata with path separators or traversal components in the build string, it can lead to path traversal, allowing package contents to be written outside the configured package cache directory. This vulnerability is identified as CWE-22 and CWE-73 and affects versions prior to 0.9.0 for rattler_cache and prior to 0.24.0 for py-rattler. The issue requires interaction with untrusted conda channels, as curated channels are expected to prevent malformed build strings.

The vulnerability allows an attacker controlling or influencing a conda channel to cause package contents to be written outside the intended cache directory on the user's filesystem. This can lead to integrity issues and potential denial of service by overwriting or placing files in unauthorized locations. There is no direct confidentiality impact reported. Exploitation requires user interaction with a malicious or untrusted channel. No known exploits are reported in the wild.

Users should upgrade to versions 0.9.0 or later for rattler_cache and 0.24.0 or later for py-rattler where this issue is fixed. Additionally, users should avoid using untrusted or malicious conda channels, relying instead on curated channels that validate package metadata to prevent malformed build strings. Patch status is not explicitly confirmed in the provided data; users should verify the vendor advisory for official fixes.