CVE-2018-10903

A flaw was found in python-cryptography versions between >=1.9.0 and <2.3.
The finalize_with_tag API did not enforce a minimum tag length. If a user
did not validate the input length prior to passing it to finalize_with_tag
an attacker could craft an invalid payload with a shortened tag (e.g. 1
byte) such that they would have a 1 in 256 chance of passing the MAC check.
GCM tag forgeries can cause key leakage.

Bugs

• <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=904072&gt;

Notes