Ubuntu: USN-4401-1 Critical: Samba Security Fix for Multiple Issues

Multiple security issues have been discoverd in Samba, a SMB/CIFS file,
print, and login server for Unix:

CVE-2017-12150

Stefan Metzmacher discovered multiple code paths where SMB signing
was not enforced.

CVE-2017-12151

Stefan Metzmacher discovered that tools using libsmbclient did not
enforce encryption when following DFS redirects, which could allow a
man-in-the-middle attacker to read or modify connections which were
meant to be encrypted.

CVE-2017-12163

Yihan Lian and Zhibin Hu discovered that insufficient range checks
in the processing of SMB1 write requests could result in disclosure
of server memory.

For the oldstable distribution (jessie), these problems have been fixed
in version 2:4.2.14+dfsg-0+deb8u8.

For the stable distribution (stretch), these problems have been fixed in
version 2:4.5.8+dfsg-2+deb9u2.

We recommend that you upgrade your samba packages.

Further information about Debian Security Advisories, how to apply
these updates to your system and fre...