Your submission was sent successfully! Close

You have successfully unsubscribed! Close

Thank you for signing up for our newsletter!
In these regular emails you will find the latest updates about Ubuntu and upcoming events where you can meet our team.Close

CVE-2021-3738

Published: 9 November 2021

In DCE/RPC it is possible to share the handles (cookies for resource state) between multiple connections via a mechanism called 'association groups'. These handles can reference connections to our sam.ldb database. However while the database was correctly shared, the user credentials state was only pointed at, and when one connection within that association group ended, the database would be left pointing at an invalid 'struct session_info'. The most likely outcome here is a crash, but it is possible that the use-after-free could instead allow different user state to be pointed at and this might allow more privileged access.

Notes

AuthorNote
mdeslaur
Fixing this in Ubuntu 18.04 LTS would require substantial
code backports. We will not be fixing this issue in Ubuntu 18.04
LTS. In environments where this is of concern, we recommend
updating to a more recent Ubuntu version.

Priority

Medium

Cvss 3 Severity Score

8.8

Score breakdown

Status

Package Release Status
samba
Launchpad, Ubuntu, Debian
bionic Ignored

focal
Released (2:4.13.14+dfsg-0ubuntu0.20.04.1)
hirsute
Released (2:4.13.14+dfsg-0ubuntu0.21.04.1)
impish
Released (2:4.13.14+dfsg-0ubuntu0.21.10.1)
jammy
Released (2:4.13.14+dfsg-0ubuntu1)
kinetic
Released (2:4.13.14+dfsg-0ubuntu1)
lunar
Released (2:4.13.14+dfsg-0ubuntu1)
trusty Ignored
(change too intrusive)
upstream
Released (4.13.14)
xenial Ignored
(change too intrusive)

Severity score breakdown

Parameter Value
Base score 8.8
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Scope Unchanged
Confidentiality High
Integrity impact High
Availability impact High
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H