First published: Thu Dec 19 2019(Updated: )
** DISPUTED ** 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.
Credit: cve@mitre.org cve@mitre.org
Affected Software | Affected Version | How to fix |
---|---|---|
Sudo Sudo | <=1.8.29 | |
<=1.8.29 |
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CVE-2019-19234 is a vulnerability in the Sudo software through version 1.8.29.
CVE-2019-19234 has a severity rating of high, with a CVSS score of 7.5.
CVE-2019-19234 allows an attacker with access to a Runas ALL sudoer account to impersonate any blocked user in Sudo.
Sudo version 1.8.29 is affected by CVE-2019-19234.
Update Sudo to a version later than 1.8.29 to fix CVE-2019-19234.