=========================================================================Ubuntu Security Notice USN-4106-1
August 20, 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

Summary:

NLTK could be made to overwrite files.

Software Description:
- nltk: Python libraries for natural language processing

Details:

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

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

References:
  https://ubuntu.com/security/notices/USN-4106-1
  CVE-2019-14751

Package Information:
  https://launchpad.net/ubuntu/+source/nltk/3.4-1ubuntu0.1
  https://launchpad.net/ubuntu/+source/nltk/3.2.5-1ubuntu0.1
  https://launchpad.net/ubuntu/+source/nltk/3.1-1ubuntu0.1