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CVE-2018-20839
systemd 242 changes the VT1 mode upon a logout, which allows attackers to read cleartext passwords in certain circumstances, such as…
- 4.3MediumCVSS base score
- 2.5%Exploitation in 30 daysEPSS · top 15% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By mitre
- 1 day later
· 1 day later
Published
- 5 years later
· 5 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Analyzed | 3.1 | Medium4.3 | CVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |
- EPSS (exploitation in 30 days)
- 2.5% · top 15% of all CVEs (11 Nov 2026)
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 4.3.
Affected products
n/a
- affected n/a
References
References6
- https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1803993 (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/systemd/systemd/commit/9725f1a10f80f5e0ae7d9b60547458622aeb322f (opens in a new tab)x_refsource_MISCx_transferred
- https://github.com/systemd/systemd/pull/12378 (opens in a new tab)x_refsource_MISCx_transferred
- 108389 (opens in a new tab)vdb-entryx_refsource_BIDx_transferred
- https://security.netapp.com/advisory/ntap-20190530-0002/ (opens in a new tab)x_refsource_CONFIRMx_transferred
- [mina-dev] 20210225 [jira] [Created] (FTPSERVER-500) Security vulnerability in common/lib/log4j-1.2.17.jar (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2018-13379 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2018-20839)Record last updated .