vulnerability
Amazon Linux 2023: CVE-2020-17049: Important priority package update for samba
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 9 | (AV:N/AC:L/Au:S/C:C/I:C/A:C) | Nov 10, 2020 | Feb 17, 2025 | Jul 9, 2025 |
Severity
9
CVSS
(AV:N/AC:L/Au:S/C:C/I:C/A:C)
Published
Nov 10, 2020
Added
Feb 17, 2025
Modified
Jul 9, 2025
Description
A security feature bypass vulnerability exists in the way Key Distribution Center (KDC) determines if a service ticket can be used for delegation via Kerberos Constrained Delegation (KCD).
To exploit the vulnerability, a compromised service that is configured to use KCD could tamper with a service ticket that is not valid for delegation to force the KDC to accept it.
The update addresses this vulnerability by changing how the KDC validates service tickets used with KCD.
It was found that the Kerberos Key Distribution Center (KDC) delegation feature, Service for User (S4U), did not sufficiently protect the tickets it's providing from tempering. A malicious, authenticated service principal allowed to delegate could use this flaw to impersonate a non-forwardable user.
To exploit the vulnerability, a compromised service that is configured to use KCD could tamper with a service ticket that is not valid for delegation to force the KDC to accept it.
The update addresses this vulnerability by changing how the KDC validates service tickets used with KCD.
It was found that the Kerberos Key Distribution Center (KDC) delegation feature, Service for User (S4U), did not sufficiently protect the tickets it's providing from tempering. A malicious, authenticated service principal allowed to delegate could use this flaw to impersonate a non-forwardable user.
Solutions
amazon-linux-2023-upgrade-libnetapiamazon-linux-2023-upgrade-libnetapi-debuginfoamazon-linux-2023-upgrade-libnetapi-develamazon-linux-2023-upgrade-libsmbclientamazon-linux-2023-upgrade-libsmbclient-debuginfoamazon-linux-2023-upgrade-libsmbclient-develamazon-linux-2023-upgrade-libwbclientamazon-linux-2023-upgrade-libwbclient-debuginfoamazon-linux-2023-upgrade-libwbclient-develamazon-linux-2023-upgrade-python3-sambaamazon-linux-2023-upgrade-python3-samba-debuginfoamazon-linux-2023-upgrade-python3-samba-develamazon-linux-2023-upgrade-python3-samba-testamazon-linux-2023-upgrade-sambaamazon-linux-2023-upgrade-samba-clientamazon-linux-2023-upgrade-samba-client-debuginfoamazon-linux-2023-upgrade-samba-client-libsamazon-linux-2023-upgrade-samba-client-libs-debuginfoamazon-linux-2023-upgrade-samba-commonamazon-linux-2023-upgrade-samba-common-libsamazon-linux-2023-upgrade-samba-common-libs-debuginfoamazon-linux-2023-upgrade-samba-common-toolsamazon-linux-2023-upgrade-samba-common-tools-debuginfoamazon-linux-2023-upgrade-samba-dcerpcamazon-linux-2023-upgrade-samba-dcerpc-debuginfoamazon-linux-2023-upgrade-samba-dc-libsamazon-linux-2023-upgrade-samba-dc-libs-debuginfoamazon-linux-2023-upgrade-samba-debuginfoamazon-linux-2023-upgrade-samba-debugsourceamazon-linux-2023-upgrade-samba-develamazon-linux-2023-upgrade-samba-krb5-printingamazon-linux-2023-upgrade-samba-krb5-printing-debuginfoamazon-linux-2023-upgrade-samba-ldb-ldap-modulesamazon-linux-2023-upgrade-samba-ldb-ldap-modules-debuginfoamazon-linux-2023-upgrade-samba-libsamazon-linux-2023-upgrade-samba-libs-debuginfoamazon-linux-2023-upgrade-samba-pidlamazon-linux-2023-upgrade-samba-testamazon-linux-2023-upgrade-samba-test-debuginfoamazon-linux-2023-upgrade-samba-test-libsamazon-linux-2023-upgrade-samba-test-libs-debuginfoamazon-linux-2023-upgrade-samba-usersharesamazon-linux-2023-upgrade-samba-vfs-iouringamazon-linux-2023-upgrade-samba-vfs-iouring-debuginfoamazon-linux-2023-upgrade-samba-winbindamazon-linux-2023-upgrade-samba-winbind-clientsamazon-linux-2023-upgrade-samba-winbind-clients-debuginfoamazon-linux-2023-upgrade-samba-winbind-debuginfoamazon-linux-2023-upgrade-samba-winbind-krb5-locatoramazon-linux-2023-upgrade-samba-winbind-krb5-locator-debuginfoamazon-linux-2023-upgrade-samba-winbind-modulesamazon-linux-2023-upgrade-samba-winbind-modules-debuginfo
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