CVE-2020-1472

Publication date 16 September 2020

Last updated 21 August 2024

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

5.5 · Medium

Score breakdown

An elevation of privilege vulnerability exists when an attacker establishes a vulnerable Netlogon secure channel connection to a domain controller, using the Netlogon Remote Protocol (MS-NRPC). An attacker who successfully exploited the vulnerability could run a specially crafted application on a device on the network. To exploit the vulnerability, an unauthenticated attacker would be required to use MS-NRPC to connect to a domain controller to obtain domain administrator access. Microsoft is addressing the vulnerability in a phased two-part rollout. These updates address the vulnerability by modifying how Netlogon handles the usage of Netlogon secure channels. For guidelines on how to manage the changes required for this vulnerability and more information on the phased rollout, see How to manage the changes in Netlogon secure channel connections associated with CVE-2020-1472 (updated September 28, 2020). When the second phase of Windows updates become available in Q1 2021, customers will be notified via a revision to this security vulnerability. If you wish to be notified when these updates are released, we recommend that you register for the security notifications mailer to be alerted of content changes to this advisory. See Microsoft Technical Security Notifications.

Read the notes from the security team

Status

Package Ubuntu Release Status
samba 20.04 LTS focal
Not affected
18.04 LTS bionic
Fixed 2:4.7.6+dfsg~ubuntu-0ubuntu2.19
16.04 LTS xenial
Fixed 2:4.3.11+dfsg-0ubuntu0.16.04.30
14.04 LTS trusty

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Notes

mdeslaur

Starting with Samba 4.8, "server schannel" defaults to "yes" instead of "auto". This is sufficient to address this vulnerability. See details in the upstream bug report. There may be an additional commit to make ServerAuthenticate3 fail so that the false positive reported by the third party vulnerability scanning tools is fixed.

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
samba

Severity score breakdown

Parameter Value
Base score 5.5 · Medium
Attack vector Local
Attack complexity Low
Privileges required Low
User interaction None
Scope Unchanged
Confidentiality High
Integrity impact None
Availability impact None
Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

References

Related Ubuntu Security Notices (USN)

Other references