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:

python3-cryptography 1.5-2ubuntu0.1

python-cryptography 1.5-2ubuntu0.1

Ubuntu 16.04 LTS:

python3-cryptography 1.2.3-1ubuntu0.1

python-cryptography 1.2.3-1ubuntu0.1

To update your system, please follow these instructions: http://ift.tt/17VXqjU.

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

References

CVE-2016-9243

from Ubuntu Security Notices http://ift.tt/2gASKaK