CVE-2024-39705

NLTK through 3.8.1 allows remote code execution if untrusted packages have pickled Python code, and the integrated data package download functionality is used. This affects, for example, averaged_perceptron_tagger and punkt.

Weakness

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

Affected Software

Potential Mitigations

• Make fields transient to protect them from deserialization.
• An attempt to serialize and then deserialize a class containing transient fields will result in NULLs where the transient data should be. This is an excellent way to prevent time, environment-based, or sensitive variables from being carried over and used improperly.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/586.html

References

• https://github.com/nltk/nltk/issues/2522
• https://github.com/nltk/nltk/issues/3266
• https://www.vicarius.io/vsociety/posts/rce-in-python-nltk-cve-2024-39705-39706
• https://github.com/nltk/nltk/issues/2522
• https://github.com/nltk/nltk/issues/3266
• https://www.vicarius.io/vsociety/posts/rce-in-python-nltk-cve-2024-39705-39706