USN-4106-1: NLTK vulnerability

20 August 2019

NLTK vulnerability

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 19.04
  • Ubuntu 18.04 LTS
  • Ubuntu 16.04 LTS


NLTK could be made to overwrite files.

Software Description

  • nltk - Python libraries for natural language processing


Mike Salvatore discovered that NLTK mishandled crafted ZIP archives during extraction. A remote attacker could use this vulnerability to write arbitrary files to the filesystem

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 19.04
python-nltk - 3.4-1ubuntu0.1
python3-nltk - 3.4-1ubuntu0.1
Ubuntu 18.04 LTS
python-nltk - 3.2.5-1ubuntu0.1
python3-nltk - 3.2.5-1ubuntu0.1
Ubuntu 16.04 LTS
python-nltk - 3.1-1ubuntu0.1
python3-nltk - 3.1-1ubuntu0.1

To update your system, please follow these instructions:

In general, a standard system update will make all the necessary changes.