CVE-2019-14847

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Last Modified: UTC

Description

A flaw was found in samba versions 4.0.0 through 4.10.0. An attacker can crash AD DC LDAP server via dirsync resulting in denial of service. Privilege escalation is not possible with this issue.

A flaw was found in samba versions 4.0.0 through 4.10.0. An attacker can crash AD DC LDAP server via dirsync resulting in denial of service. Privilege escalation is not possible with this issue.

Statement

This flaw does not affect the version of samba shipped with Red Hat Enterprise Linux because there is no support for samba as Active Directory Domain Controller.

This flaw does not affect the version of samba shipped with Red Hat Enterprise Linux because there is no support for samba as Active Directory Domain Controller.

Mitigation

By default, the supported versions of Samba impacted by this issue run using the "standard" process model, which is unaffected. This is controlled by the -M or --model parameter to the samba binary. Unsupported Samba versions before Samba 4.7 use a single process for the LDAP server, and so are impacted. Samba 4.8, 4.9, and 4.10 are impacted if -M prefork or -M single is used. To mitigate this issue, select -M standard (the default).

Additional information

  • Bugzilla 1764142: samba: samba AD DC LDAP denial of service via dirsync
  • CWE-476: NULL Pointer Dereference
  • FAQ: Frequently asked questions about CVE-2019-14847

Common Vulnerability Scoring System (CVSS) Score Details

Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 Score Breakdown
Red HatNVD

CVSS v3 Base Score

4.9

4.9

Attack Vector

Network

Network

Attack Complexity

Low

Low

Privileges Required

High

High

User Interaction

None

None

Scope

Unchanged

Unchanged

Confidentiality Impact

None

None

Integrity Impact

None

None

Availability Impact

High

High

CVSS v3 Vector

Red Hat: CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

NVD: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

Acknowledgements

Red Hat would like to thank the Samba project for reporting this issue. Upstream acknowledges Adam Xu as the original reporter.

Frequently Asked Questions

Why is Red Hat's CVSS v3 score or Impact different from other vendors?

My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?

What can I do if my product is listed as "Will not fix"?

What can I do if my product is listed as "Fix deferred"?

What is a mitigation?

I have a Red Hat product but it is not in the above list, is it affected?

Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?

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