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
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Nltk | Ubuntu | esm-apps-legacy/xenial | * |
| Nltk | Ubuntu | esm-apps/bionic | * |
| Nltk | Ubuntu | esm-apps/focal | * |
| Nltk | Ubuntu | esm-apps/jammy | * |
| Nltk | Ubuntu | esm-apps/noble | * |
| Nltk | Ubuntu | esm-apps/xenial | * |
| Nltk | Ubuntu | esm-infra-legacy/trusty | * |
| Nltk | Ubuntu | focal | * |
| Nltk | Ubuntu | jammy | * |
| Nltk | Ubuntu | mantic | * |
| Nltk | Ubuntu | noble | * |
| Nltk | Ubuntu | oracular | * |
| Nltk | Ubuntu | trusty/esm | * |
| Nltk | Ubuntu | upstream | * |
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
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