MEDIUM
CVE-2018-20839
NVD-CWE-noinfoPublished: May 17, 2019· Updated: Jun 17, 2026
4.3
CVSS v3.1
Official 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.
Technical Analysis
CVE-2018-20839 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.
A successful exploit results in complete confidentiality breach (data exposure), with a CVSS base score of 4.3.
CVSS v3.1 Vector Breakdown
Exploitability
Attack VectorPhysical
Attack ComplexityLow
Privileges Req.None
User InteractionRequired
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityNone
AvailabilityNone
CVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Affected Vendors & Products
netapp4 product(s)
cn1610 firmwarecn1610snapprotectsolidfire \& hci management node
systemd_project1 product(s)
systemd
Source: NVD CPE · 5 total CPE entries
Exploit & PoC Resources
NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.
Official Patches & Advisories
All References (12)
→
http://www.securityfocus.com/bid/108389Broken Link · Third Party Advisory · VDB Entry
→
https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1803993Issue Tracking · Third Party Advisory
→
https://github.com/systemd/systemd/pull/12378Issue Tracking · Patch
→
https://security.netapp.com/advisory/ntap-20190530-0002/Third Party Advisory
→
http://www.securityfocus.com/bid/108389Broken Link · Third Party Advisory · VDB Entry
→
https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1803993Issue Tracking · Third Party Advisory
→
https://github.com/systemd/systemd/pull/12378Issue Tracking · Patch
→
https://security.netapp.com/advisory/ntap-20190530-0002/Third Party Advisory
Quick Facts
CVE IDCVE-2018-20839
CVSS Score4.3 / 10
SeverityMEDIUM
WeaknessNVD-CWE-noinfo
CISA KEVNo
Affected2 vendor(s)
PublishedMay 17, 2019
Related CVEs (NVD-CWE-noinfo)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2018-20839 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.