UBUNTU-CVE-2019-19234 (CVE-2019-19234)
Vulnerability from osv_ubuntu – Published: 2019-12-19 21:15 – Updated: 2025-09-08 16:45 – Source websiteIn Sudo through 1.8.29, the fact that a user has been blocked (e.g., by using the ! character in the shadow file instead of a password hash) is not considered, allowing an attacker (who has access to a Runas ALL sudoer account) to impersonate any blocked user. NOTE: The software maintainer believes that this CVE is not valid. Disabling local password authentication for a user is not the same as disabling all access to that user--the user may still be able to login via other means (ssh key, kerberos, etc). Both the Linux shadow(5) and passwd(1) manuals are clear on this. Indeed it is a valid use case to have local accounts that are only accessible via sudo and that cannot be logged into with a password. Sudo 1.8.30 added an optional setting to check the shell of the target user (not the encrypted password!) against the contents of /etc/shells but that is not the same thing as preventing access to users with an invalid password hash
| URL | Type | |
|---|---|---|
{
"affected": [
{
"ecosystem_specific": {
"availability": "No subscription required",
"binaries": [
{
"binary_name": "sudo",
"binary_version": "1.8.31-1ubuntu1"
},
{
"binary_name": "sudo-ldap",
"binary_version": "1.8.31-1ubuntu1"
}
]
},
"package": {
"ecosystem": "Ubuntu:20.04:LTS",
"name": "sudo",
"purl": "pkg:deb/ubuntu/sudo@1.8.31-1ubuntu1?arch=source\u0026distro=focal"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.8.31-1ubuntu1"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.8.27-1ubuntu4",
"1.8.29-1ubuntu1"
]
}
],
"aliases": [],
"details": "In Sudo through 1.8.29, the fact that a user has been blocked (e.g., by using the ! character in the shadow file instead of a password hash) is not considered, allowing an attacker (who has access to a Runas ALL sudoer account) to impersonate any blocked user. NOTE: The software maintainer believes that this CVE is not valid. Disabling local password authentication for a user is not the same as disabling all access to that user--the user may still be able to login via other means (ssh key, kerberos, etc). Both the Linux shadow(5) and passwd(1) manuals are clear on this. Indeed it is a valid use case to have local accounts that are _only_ accessible via sudo and that cannot be logged into with a password. Sudo 1.8.30 added an optional setting to check the _shell_ of the target user (not the encrypted password!) against the contents of /etc/shells but that is not the same thing as preventing access to users with an invalid password hash",
"id": "UBUNTU-CVE-2019-19234",
"modified": "2025-09-08T16:45:43Z",
"published": "2019-12-19T21:15:00Z",
"references": [
{
"type": "REPORT",
"url": "https://ubuntu.com/security/CVE-2019-19234"
},
{
"type": "REPORT",
"url": "https://www.sudo.ws/devel.html#1.8.30b2"
},
{
"type": "REPORT",
"url": "https://www.sudo.ws/stable.html"
},
{
"type": "REPORT",
"url": "https://www.cve.org/CVERecord?id=CVE-2019-19234"
}
],
"related": [],
"schema_version": "1.7.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
},
{
"score": "low",
"type": "Ubuntu"
}
],
"upstream": [
"CVE-2019-19234"
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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