Bug 2046134 (CVE-2022-0336)

Summary: CVE-2022-0336 samba: Samba AD users with permission to write to an account can impersonate arbitrary services
Product: [Other] Security Response Reporter: Huzaifa S. Sidhpurwala <huzaifas>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED NOTABUG QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: abokovoy, anoopcs, asn, dkarpele, gdeschner, hvyas, iboukris, jarrpa, jstephen, lmohanty, madam, pfilipen, rhs-smb, sbose, security-response-team, ssorce
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Fixed In Version: samba 4.13.17, samba 4.14.12, samba 4.15.4 Doc Type: If docs needed, set a value
Doc Text:
A logic flaw in the Samba Active Directory Domain Controller leads to a denial of service and service impersonation. This flaw allows an attacker with the ability to write to an account to perform a denial of service attack or service impersonation by adding an SPN that matches an existing service.
Story Points: ---
Clone Of: Environment:
Last Closed: 2022-01-31 15:01:05 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On: 2048568    
Bug Blocks: 2046121    

Description Huzaifa S. Sidhpurwala 2022-01-26 10:09:54 UTC
As per samba upstream advisory:

The Samba AD DC includes checks when adding service principals names (SPNs) to an account to ensure that SPNs do not alias with those already in the database. Some of these checks are able to be bypassed if an account modification re-adds an SPN that was previously present on that account, such as one added when a computer is joined to a domain.

An attacker who has the ability to write to an account can exploit this to perform a denial-of-service attack by adding an SPN that matches an existing service. Additionally, an attacker who can intercept traffic can impersonate existing services, resulting in a loss of confidentiality and integrity.

Comment 1 Huzaifa S. Sidhpurwala 2022-01-31 14:23:04 UTC
Created samba tracking bugs for this issue:

Affects: fedora-all [bug 2048568]

Comment 2 Product Security DevOps Team 2022-01-31 15:01:03 UTC
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):