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:
https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.