USN-3138-1: python-cryptography vulnerability

Ubuntu Security Notice USN-3138-1

28th November, 2016

python-cryptography vulnerability

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

• Ubuntu 16.10



• Ubuntu 16.04 LTS

Summary

python-cryptography could generate incorrect keys.

Software description

• python-cryptography
  - Cryptography Python library
  
  

Details

Markus Döring discovered that python-cryptography incorrectly handled
certain HKDF lengths. This could result in python-cryptography returning an
empty string instead of the expected derived key.

Update instructions

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

Ubuntu 16.10:

Ubuntu 16.04 LTS:

To update your system, please follow these instructions: