CVE-2021-3738

Publication date 9 November 2021

Last updated 24 July 2024

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

8.8 · High

Score breakdown

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.

Read the notes from the security team

Status

Package Ubuntu Release Status
samba 23.04 lunar
Fixed 2:4.13.14+dfsg-0ubuntu1
22.10 kinetic
Fixed 2:4.13.14+dfsg-0ubuntu1
22.04 LTS jammy
Fixed 2:4.13.14+dfsg-0ubuntu1
21.10 impish
Fixed 2:4.13.14+dfsg-0ubuntu0.21.10.1
21.04 hirsute
Fixed 2:4.13.14+dfsg-0ubuntu0.21.04.1
20.04 LTS focal
Fixed 2:4.13.14+dfsg-0ubuntu0.20.04.1
18.04 LTS bionic Ignored
16.04 LTS xenial Ignored change too intrusive
14.04 LTS trusty Ignored end of ESM support, was ignored [change too intrusive]

Notes

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.

Severity score breakdown

Parameter Value
Base score 8.8 · High
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