CVE-2018-20839
Estado: AnalizadaMedia (4.3)—
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.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
- Puntuación base: 4.3
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 2.48%
- Percentil entre todas las CVEs puntuadas: 84
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (4)
CWE
- NVD-CWE-noinfo
Referencias
- http://www.securityfocus.com/bid/108389
- https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1803993
- https://github.com/systemd/systemd/commit/9725f1a10f80f5e0ae7d9b60547458622aeb322f
- https://github.com/systemd/systemd/pull/12378
- https://lists.apache.org/thread.html/rf9fa47ab66495c78bb4120b0754dd9531ca2ff0430f6685ac9b07772%40%3Cdev.mina.apache.org%3E
- https://security.netapp.com/advisory/ntap-20190530-0002/
- http://www.securityfocus.com/bid/108389
- https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1803993
- https://github.com/systemd/systemd/commit/9725f1a10f80f5e0ae7d9b60547458622aeb322f
- https://github.com/systemd/systemd/pull/12378
- https://lists.apache.org/thread.html/rf9fa47ab66495c78bb4120b0754dd9531ca2ff0430f6685ac9b07772%40%3Cdev.mina.apache.org%3E
- https://security.netapp.com/advisory/ntap-20190530-0002/
JSON original (NVD)
Mostrar
{
"id": "CVE-2018-20839",
"cveTags": [],
"metrics": {
"cvssMetricV2": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"version": "2.0",
"baseScore": 4.3,
"accessVector": "NETWORK",
"vectorString": "AV:N/AC:M/Au:N/C:P/I:N/A:N",
"authentication": "NONE",
"integrityImpact": "NONE",
"accessComplexity": "MEDIUM",
"availabilityImpact": "NONE",
"confidentialityImpact": "PARTIAL"
},
"acInsufInfo": false,
"impactScore": 2.9,
"baseSeverity": "MEDIUM",
"obtainAllPrivilege": false,
"exploitabilityScore": 8.6,
"obtainUserPrivilege": false,
"obtainOtherPrivilege": false,
"userInteractionRequired": false
}
],
"cvssMetricV31": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 4.3,
"attackVector": "PHYSICAL",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N",
"integrityImpact": "NONE",
"userInteraction": "REQUIRED",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 3.6,
"exploitabilityScore": 0.7
}
]
},
"affected": [
{
"source": "cve@mitre.org",
"affectedData": [
{
"vendor": "n/a",
"product": "n/a",
"versions": [
{
"status": "affected",
"version": "n/a"
}
]
}
]
}
],
"published": "2019-05-17T04:29:00.933",
"references": [
{
"url": "http://www.securityfocus.com/bid/108389",
"tags": [
"Broken Link",
"Third Party Advisory",
"VDB Entry"
],
"source": "cve@mitre.org"
},
{
"url": "https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1803993",
"tags": [
"Issue Tracking",
"Third Party Advisory"
],
"source": "cve@mitre.org"
},
{
"url": "https://github.com/systemd/systemd/commit/9725f1a10f80f5e0ae7d9b60547458622aeb322f",
"tags": [
"Patch"
],
"source": "cve@mitre.org"
},
{
"url": "https://github.com/systemd/systemd/pull/12378",
"tags": [
"Issue Tracking",
"Patch"
],
"source": "cve@mitre.org"
},
{
"url": "https://lists.apache.org/thread.html/rf9fa47ab66495c78bb4120b0754dd9531ca2ff0430f6685ac9b07772%40%3Cdev.mina.apache.org%3E",
"tags": [
"Mailing List"
],
"source": "cve@mitre.org"
},
{
"url": "https://security.netapp.com/advisory/ntap-20190530-0002/",
"tags": [
"Third Party Advisory"
],
"source": "cve@mitre.org"
},
{
"url": "http://www.securityfocus.com/bid/108389",
"tags": [
"Broken Link",
"Third Party Advisory",
"VDB Entry"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1803993",
"tags": [
"Issue Tracking",
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://github.com/systemd/systemd/commit/9725f1a10f80f5e0ae7d9b60547458622aeb322f",
"tags": [
"Patch"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://github.com/systemd/systemd/pull/12378",
"tags": [
"Issue Tracking",
"Patch"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://lists.apache.org/thread.html/rf9fa47ab66495c78bb4120b0754dd9531ca2ff0430f6685ac9b07772%40%3Cdev.mina.apache.org%3E",
"tags": [
"Mailing List"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://security.netapp.com/advisory/ntap-20190530-0002/",
"tags": [
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Analyzed",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "NVD-CWE-noinfo"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "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."
},
{
"lang": "es",
"value": "El systemd 242 cambia el VT1 mode al terminar la sesión, esto permite a los atacantes leer contraseñas de texto simple en algunas circunstancias, tales como ver un apagado o usar Ctrl-Alt-F1 y Ctrl-Alt-F2. Esto ocurre porque la comprobación KDGKBMODE (también conocido como modo de teclado actual) es manejada incorrectamente."
}
],
"lastModified": "2026-06-17T01:53:34.263",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:systemd_project:systemd:242:-:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "A00408E2-96BE-44A7-A389-90C6F6DE8157"
}
],
"operator": "OR"
}
]
},
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:netapp:cn1610_firmware:-:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "EB30733E-68FC-49C4-86C0-7FEE75C366BF"
}
],
"operator": "OR"
},
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:h:netapp:cn1610:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "6361DAC6-600F-4B15-8797-D67F298F46FB"
}
],
"operator": "OR"
}
],
"operator": "AND"
},
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:netapp:snapprotect:-:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "F74F467A-0C81-40D9-BA06-40FB8EF02C04"
},
{
"criteria": "cpe:2.3:a:netapp:solidfire_\\&_hci_management_node:-:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "D6D700C5-F67F-4FFB-BE69-D524592A3D2E"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "cve@mitre.org"
}