Bug 1625449 (CVE-2018-14629)

Summary:	CVE-2018-14629 samba: Unprivileged adding of CNAME record causing loop in AD LDAP server
Product:	[Other] Security Response	Reporter:	Sam Fowler <sfowler>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	abhgupta, abokovoy, anoopcs, asn, bmcclain, dbaker, dblechte, dfediuck, eedri, gdeschner, jarrpa, jokerman, jstephen, lmohanty, madam, mgoldboi, michal.skrivanek, rhs-smb, sankarshan, sbonazzo, sbose, security-response-team, sherold, sisharma, ssaha, ssorce, sthangav, trankin, vbellur
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	samba 4.7.12, samba 4.8.7, samba 4.9.3	Doc Type:	If docs needed, set a value
Doc Text:	A denial of service vulnerability was discovered in Samba's LDAP server. A CNAME loop could lead to infinite recursion in the server. An unprivileged local attacker could create such an entry, leading to denial of service.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-06-10 10:37:26 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1654078
Bug Blocks:	1625448

Description Sam Fowler 2018-09-05 00:46:03 UTC

All versions of Samba from 4.0.0 onwards are vulnerable infinite query recursion caused by CNAME loops.  Any dns record can be added via ldap by an unprivileged user using the ldbadd tool, so this is a security issue.

Comment 1 Sam Fowler 2018-09-05 00:46:05 UTC

Acknowledgments:

Name: Andrew Bartlett (Catalyst and Samba Team)
Upstream: Florian Stülpner (HiperScan)

Comment 2 Doran Moppert 2018-09-05 04:17:04 UTC

Upstream bug:

https://bugzilla.samba.org/show_bug.cgi?id=13600

Comment 3 Doran Moppert 2018-09-05 04:17:14 UTC

Statement:

Samba 4 packages distributed with Red Hat Enterprise Linux are built without the AD DC functionality, where this flaw is present.  These packages are not affected by this vulnerability.

Comment 4 Sam Fowler 2018-11-28 01:51:03 UTC

External Reference:

https://www.samba.org/samba/security/CVE-2018-14629.html

Comment 5 Sam Fowler 2018-11-28 01:51:37 UTC

Created samba tracking bugs for this issue:

Affects: fedora-all [bug 1654078]