Bug#834367: systemctl daemon-reexec (as run on systemd upgrade) causes all keystrokes to go to text console in addition to X (including passwords)

[Josh Triplett]

Package: systemd
Version: 231-2
Severity: critical
Tags: security

[Severity and tag due to the likely possibility of exposing user
passwords this way.  If this occurs with the version in jessie as well,
it'll require a security update.]

After running "systemctl daemon-reexec" from within an X session, all
keystrokes in the X session (including passwords) appear on the
underlying text console as well.  They show up during the shutdown
process, or any other time X stops.

Since systemd's postinst runs "systemctl daemon-reexec" on upgrades,
this would occur in any session after upgrading the systemd package.

I can reliably reproduce this, either by upgrading or downgrading the
systemd package, or by running "systemctl daemon-reexec" (as root).

This might potentially explain the mention in bug 819500 of seeing
usernames and passwords on the console, as well.  This would only happen
in a session after upgrading systemd or otherwise running "systemctl
daemon-reexec", which would explain not seeing it every time.

-- Package-specific info:

-- System Information:
Debian Release: stretch/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 4.7.0-rc7-amd64 (SMP w/4 CPU cores)
Locale: LANG=C.UTF-8, LC_CTYPE=C.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages systemd depends on:
ii  adduser         3.115
ii  libacl1         2.2.52-3
ii  libapparmor1    2.10.95-4
ii  libaudit1       1:2.6.5-1
ii  libblkid1       2.28-6
ii  libc6           2.23-4
ii  libcap2         1:2.25-1
ii  libcap2-bin     1:2.25-1
ii  libcryptsetup4  2:1.7.0-2
ii  libgcrypt20     1.7.2-2
ii  libgpg-error0   1.24-1
ii  libidn11        1.33-1
ii  libkmod2        22-1.1
ii  liblzma5        5.1.1alpha+20120614-2.1
ii  libmount1       2.28-6
ii  libpam0g        1.1.8-3.3
ii  libseccomp2     2.3.1-2
ii  libselinux1     2.5-3
ii  libsystemd0     231-2
ii  mount           2.28-6
ii  util-linux      2.28-6

Versions of packages systemd recommends:
ii  dbus            1.10.8-1
ii  libpam-systemd  231-2

Versions of packages systemd suggests:
ii  policykit-1        0.105-16
pn  systemd-container  <none>
pn  systemd-ui         <none>

Versions of packages systemd is related to:
ii  udev  231-2

-- no debconf information