=========================================================================Ubuntu Security Notice USN-4196-1
November 18, 2019

python-ecdsa vulnerabilities
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 19.10
- Ubuntu 19.04
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

Several security issues were fixed in python-ecdsa.

Software Description:
- python-ecdsa: ECDSA cryptographic signature library

Details:

It was discovered that python-ecdsa incorrectly handled certain signatures.
A remote attacker could possibly use this issue to cause python-ecdsa to
generate unexpected exceptions, resulting in a denial of service.
(CVE-2019-14853)

It was discovered that python-ecdsa incorrectly verified DER encoding in
signatures. A remote attacker could use this issue to perform certain
malleability attacks. (CVE-2019-14859)

Update instructions:

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

Ubuntu 19.10:
  python-ecdsa                    0.13.2-2ubuntu0.1
  python3-ecdsa                   0.13.2-2ubuntu0.1

Ubuntu 19.04:
  python-ecdsa                    0.13-3ubuntu0.1
  python3-ecdsa                   0.13-3ubuntu0.1

Ubuntu 18.04 LTS:
  python-ecdsa                    0.13-2ubuntu0.18.04.1
  python3-ecdsa                   0.13-2ubuntu0.18.04.1

Ubuntu 16.04 LTS:
  python-ecdsa                    0.13-2ubuntu0.16.04.1
  python3-ecdsa                   0.13-2ubuntu0.16.04.1

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

References:
  https://ubuntu.com/security/notices/USN-4196-1
  CVE-2019-14853, CVE-2019-14859

Package Information:
  https://launchpad.net/ubuntu/+source/python-ecdsa/0.13.2-2ubuntu0.1
  https://launchpad.net/ubuntu/+source/python-ecdsa/0.13-3ubuntu0.1
  https://launchpad.net/ubuntu/+source/python-ecdsa/0.13-2ubuntu0.18.04.1
  https://launchpad.net/ubuntu/+source/python-ecdsa/0.13-2ubuntu0.16.04.1