[USN-3407-1] PyJWT vulnerability

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Ubuntu Security Notice USN-3407-1
August 30, 2017

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

- Ubuntu 17.04
- Ubuntu 16.04 LTS

Summary:

PyJWT could be made to crash if it received specially crafted
input.

Software Description:
- pyjwt: Python implementation of JSON Web Token

Details:

It was discovered that a vulnerability in PyJWT doesn't check
invalid_strings properly for some public keys. A remote attacker
could take advantage of a key confusion to craft JWTs from scratch.

Update instructions:

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

Ubuntu 17.04:
  python-jwt                      1.4.2-1ubuntu0.1
  python3-jwt                     1.4.2-1ubuntu0.1

Ubuntu 16.04 LTS:
  python-jwt                      1.3.0-1ubuntu0.1
  python3-jwt                     1.3.0-1ubuntu0.1

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

References:
  https://www.ubuntu.com/usn/usn-3407-1
  CVE-2017-11424

Package Information:
  https://launchpad.net/ubuntu/+source/pyjwt/1.4.2-1ubuntu0.1
  https://launchpad.net/ubuntu/+source/pyjwt/1.3.0-1ubuntu0.1