CVE-2019-19234
Sudo Impersonation Vulnerability
Description
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
INFO
Published Date :
Dec. 19, 2019, 9:15 p.m.
Last Modified :
Aug. 5, 2024, 2:16 a.m.
Source :
[email protected]
Remotely Exploitable :
Yes !
Impact Score :
3.6
Exploitability Score :
3.9
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2019-19234.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2019-19234 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2019-19234 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
Aug. 05, 2024
Action Type Old Value New Value -
CVE Modified by [email protected]
May. 17, 2024
Action Type Old Value New Value -
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
CVE Modified by [email protected]
Apr. 11, 2024
Action Type Old Value New Value -
CVE Modified by [email protected]
Mar. 21, 2024
Action Type Old Value New Value Added Tag MITRE disputed -
CVE Modified by [email protected]
Nov. 07, 2023
Action Type Old Value New Value Changed Description ** 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. 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 Added Reference MITRE https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IY6DZ7WMDKU4ZDML6MJLDAPG42B5WVUC/ [No types assigned] Added Reference MITRE https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I6TKF36KOQUVJNBHSVJFA7BU3CCEYD2F/ [No types assigned] Removed Reference MITRE https://lists.fedoraproject.org/archives/list/[email protected]/message/IY6DZ7WMDKU4ZDML6MJLDAPG42B5WVUC/ Removed Reference MITRE https://lists.fedoraproject.org/archives/list/[email protected]/message/I6TKF36KOQUVJNBHSVJFA7BU3CCEYD2F/ -
CVE Modified by [email protected]
Apr. 23, 2020
Action Type Old Value New Value Added Reference https://www.oracle.com/security-alerts/bulletinapr2020.html [No Types Assigned] -
CVE Modified by [email protected]
Mar. 17, 2020
Action Type Old Value New Value Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/I6TKF36KOQUVJNBHSVJFA7BU3CCEYD2F/ [No Types Assigned] -
CVE Modified by [email protected]
Mar. 06, 2020
Action Type Old Value New Value Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/IY6DZ7WMDKU4ZDML6MJLDAPG42B5WVUC/ [No Types Assigned] -
CVE Modified by [email protected]
Jan. 31, 2020
Action Type Old Value New Value Added Reference https://access.redhat.com/security/cve/cve-2019-19234 [No Types Assigned] -
CVE Modified by [email protected]
Jan. 31, 2020
Action Type Old Value New Value Added Reference https://support2.windriver.com/index.php?page=cve&on=view&id=CVE-2019-19234 [No Types Assigned] Added Reference https://www.bsi.bund.de/SharedDocs/Warnmeldungen/DE/CB/2019/12/warnmeldung_cb-k20-0001.html [No Types Assigned] Added Reference https://support2.windriver.com/index.php?page=defects&on=view&id=LIN1019-3816 [No Types Assigned] Added Reference https://www.suse.com/security/cve/CVE-2019-19234/ [No Types Assigned] Added Reference https://quickview.cloudapps.cisco.com/quickview/bug/CSCvs58812 [No Types Assigned] Added Reference https://quickview.cloudapps.cisco.com/quickview/bug/CSCvs58772 [No Types Assigned] Added Reference https://quickview.cloudapps.cisco.com/quickview/bug/CSCvs58104 [No Types Assigned] Added Reference https://support2.windriver.com/index.php?page=defects&on=view&id=LIN1018-5505 [No Types Assigned] Added Reference https://www.tenable.com/plugins/nessus/132985 [No Types Assigned] Added Reference https://quickview.cloudapps.cisco.com/quickview/bug/CSCvs58473 [No Types Assigned] Added Reference https://quickview.cloudapps.cisco.com/quickview/bug/CSCvs58979 [No Types Assigned] Added Reference https://quickview.cloudapps.cisco.com/quickview/bug/CSCvs60748 [No Types Assigned] -
CVE Modified by [email protected]
Jan. 30, 2020
Action Type Old Value New Value Changed Description 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. ** 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. -
CVE Modified by [email protected]
Jan. 03, 2020
Action Type Old Value New Value Added Reference https://security.netapp.com/advisory/ntap-20200103-0004/ [No Types Assigned] -
Initial Analysis by [email protected]
Dec. 31, 2019
Action Type Old Value New Value Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:N/I:P/A:N) Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N Changed Reference Type https://www.sudo.ws/devel.html#1.8.30b2 No Types Assigned https://www.sudo.ws/devel.html#1.8.30b2 Vendor Advisory Changed Reference Type https://www.sudo.ws/stable.html No Types Assigned https://www.sudo.ws/stable.html Vendor Advisory Added CWE NIST NVD-CWE-noinfo Added CPE Configuration OR *cpe:2.3:a:sudo:sudo:*:*:*:*:*:*:*:* versions up to (including) 1.8.29
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2019-19234 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2019-19234
weaknesses.
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
0.76 }} 0.01%
score
0.81804
percentile