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.
Priority
Medium
CVSS 3 base score: 9.8
Status
| Package | Release | Status |
|---|---|---|
|
systemd Launchpad, Ubuntu, Debian |
Upstream |
Needed
|
| Ubuntu 21.04 (Hirsute Hippo) |
Not vulnerable
|
|
| Ubuntu 20.04 LTS (Focal Fossa) |
Not vulnerable
|
|
| Ubuntu 18.04 LTS (Bionic Beaver) |
Not vulnerable
|
|
| Ubuntu 16.04 ESM (Xenial Xerus) |
Not vulnerable
|
|
| Ubuntu 14.04 ESM (Trusty Tahr) |
Not vulnerable
|
|
|
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 |
||
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. |
References
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-20839
- https://github.com/systemd/systemd/pull/12378
- https://github.com/systemd/systemd/pull/13109
- NVD
- Launchpad
- Debian