CVE-2019-19234
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
EPSS 4.08% · 88.8th percentile
Risk Scores
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Ubuntu:20.04:LTS | sudo | 0, 1.8.29-1ubuntu1, 1.8.27-1ubuntu4 |
Timeline
- Dec 19, 2019 CVE Published
- Apr 14, 2021 EPSS Score
- Jun 23, 2021 EPSS Score
- Oct 26, 2021 EPSS Score
- Dec 27, 2021 EPSS Score
- Jan 6, 2022 EPSS Score
- Feb 28, 2022 EPSS Score
- Apr 1, 2022 EPSS Score
- May 1, 2022 EPSS Score
- Jul 3, 2022 EPSS Score
- Nov 6, 2022 EPSS Score
- Jan 8, 2023 EPSS Score
References
- https://ubuntu.com/security/CVE-2019-19234 third-party-advisory
- https://www.sudo.ws/devel.html#1.8.30b2 third-party-advisory
- https://www.sudo.ws/stable.html third-party-advisory
- https://www.cve.org/CVERecord?id=CVE-2019-19234 third-party-advisory