Debian 9: DSA-4307-1 Critical: Python3.5 DoS And Buffer Overflow Fixes

Multiple security issues were discovered in Python: ElementTree failed
to initialise Expat's hash salt, two denial of service issues were found
in difflib and poplib and a buffer overflow in PyString_DecodeEscape.

For the stable distribution (stretch), these problems have been fixed in
version 3.5.3-1+deb9u1.

We recommend that you upgrade your python3.5 packages.

For the detailed security status of python3.5 please refer to
its security tracker page at:

Further information about Debian Security Advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://www.debian.org/security/