Bug 2013080 (CVE-2021-3671)

Summary: CVE-2021-3671 samba: Null pointer dereference on missing sname in TGS-REQ
Product: [Other] Security Response Reporter: Huzaifa S. Sidhpurwala <huzaifas>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED NOTABUG QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: abokovoy, anoopcs, asn, dkarpele, gdeschner, hvyas, iboukris, jrivera, jstephen, lmohanty, madam, puebele, rhs-smb, sbose, ssorce
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: samba 4.13.12, samba 4.14.8 Doc Type: If docs needed, set a value
Doc Text:
A null pointer de-reference was found in the way samba kerberos server handled missing sname in TGS-REQ (Ticket Granting Server - Request). An authenticated user could use this flaw to crash the samba server.
Story Points: ---
Clone Of: Environment:
Last Closed: 2021-10-12 08:03:29 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: 2013081    
Bug Blocks: 1988195, 2013082    

Description Huzaifa S. Sidhpurwala 2021-10-12 04:04:58 UTC
Samba's use of Heimdal was vulnerable to a null pointer de-reference flaw due to missing sname in TGS-REQ. 

This is already fixed in upstream Heimdal via:
https://github.com/heimdal/heimdal/commit/04171147948d0a3636bc6374181926f0fb2ec83a

Comment 1 Huzaifa S. Sidhpurwala 2021-10-12 04:05:51 UTC
Created samba tracking bugs for this issue:

Affects: fedora-all [bug 2013081]