CVE-2018-20839
Published: 17 May 2019
systemd 242 changes the VT1 mode upon a logout, which allows attackers to read cleartext passwords in certain circumstances, such as watching a shutdown, or using Ctrl-Alt-F1 and Ctrl-Alt-F2. This occurs because the KDGKBMODE (aka current keyboard mode) check is mishandled.
Notes
Author | Note |
---|---|
seth-arnold | Possible regression when running startx manually |
mdeslaur | commit was reverted in (240-6ubuntu7) possibly a bug in plymouth, not systemd as of 2021-04-12, we can no longer reproduce this issue with all updates applied. I am therefore marking this CVE as not affecting systemd and closing it out. This was possibly fixed by the plymouth change in bug 1817738. |
Priority
Status
Package | Release | Status |
---|---|---|
systemd Launchpad, Ubuntu, Debian |
impish |
Not vulnerable
|
bionic |
Not vulnerable
|
|
groovy |
Not vulnerable
|
|
trusty |
Not vulnerable
|
|
xenial |
Not vulnerable
|
|
jammy |
Not vulnerable
|
|
cosmic |
Ignored
(end of life)
|
|
disco |
Ignored
(end of life)
|
|
eoan |
Ignored
(end of life)
|
|
focal |
Not vulnerable
|
|
hirsute |
Not vulnerable
|
|
upstream |
Needed
|
|
Patches: upstream: https://github.com/systemd/systemd/commit/9725f1a10f80f5e0ae7d9b60547458622aeb322f upstream: https://github.com/systemd/systemd/commit/bb5ac84d79ac3aef606a4a9eeaafef94a1f199be upstream: https://github.com/systemd/systemd/commit/13a43c73d8cbac4b65472de04bb88ea1bacdeb89 |
Severity score breakdown
Parameter | Value |
---|---|
Base score | 9.8 |
Attack vector | Network |
Attack complexity | Low |
Privileges required | None |
User interaction | None |
Scope | Unchanged |
Confidentiality | High |
Integrity impact | High |
Availability impact | High |
Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |