In Sudo through 1.8.29, the fact that a user has been blocked (e.g., by using the !…
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Partial Red Hat: 1 fixed, 3 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.
Summary
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
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
Remediation
Red Hat 1 advisory
- RHSA-2020:1804 Released 2020-04-28 · Red Hat rating Moderatesudo security, bug fix, and enhancement update
- Red Hat Enterprise Linux BaseOS (v. 8) sudo-1.8.29-5.el8
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 5 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2020:1804 |
Timeline
- 2026-10-02 Threatist record created from CVE-2019-19234
- 2026-10-03 Alias added: GHSA-vh47-792w-24m4
References
Advisory 4
Other 15
- https://security.netapp.com/advisory/ntap-20200103-0004/
- https://support2.windriver.com/index.php?page=defects&on=view&id=LIN1018-5505
- https://quickview.cloudapps.cisco.com/quickview/bug/CSCvs58104
- https://quickview.cloudapps.cisco.com/quickview/bug/CSCvs58473
- https://quickview.cloudapps.cisco.com/quickview/bug/CSCvs58812
- https://quickview.cloudapps.cisco.com/quickview/bug/CSCvs58979
- https://quickview.cloudapps.cisco.com/quickview/bug/CSCvs58772
- https://quickview.cloudapps.cisco.com/quickview/bug/CSCvs60748
- https://www.tenable.com/plugins/nessus/132985
- https://support2.windriver.com/index.php?page=defects&on=view&id=LIN1019-3816
- https://support2.windriver.com/index.php?page=cve&on=view&id=CVE-2019-19234
- https://www.suse.com/security/cve/CVE-2019-19234/
- https://www.bsi.bund.de/SharedDocs/Warnmeldungen/DE/CB/2019/12/warnmeldung_cb-k20-0001.html
- https://access.redhat.com/security/cve/cve-2019-19234
- https://www.oracle.com/security-alerts/bulletinapr2020.html
More Sudo vulnerabilities
- TI-2019-13862 In Sudo through 1.8.29, an attacker with access to a Runas ALL sudoer account can… CVSS 3.1HIGH 7.5
Sources
- CVE-2019-19234 · CVE Program
- CVE-2019-19234 · NVD
- FIRST EPSS
- GHSA-vh47-792w-24m4 · GitHub Advisory Database · CC BY 4.0
- CVE-2019-19234 · Red Hat security data · CC BY 4.0
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