Vulnerability Details

ISC BIND DoS Vulnerability - CVE-2019-6477 (Windows)

Published: 2019-11-22 03:02:09
CVE Author: NIST National Vulnerability Database

CVSS Base Vector:

Detection Type:
Remote Banner

Solution Type:
Vendor Patch

ISC BIND is prone to a denial of service vulnerability as TCP-pipelined queries can bypass tcp-clients limit.

Detection Method:
Checks if a vulnerable version is present on the target host.

Technical Details:
By design, BIND is intended to limit the number of TCP clients that can be connected at any given time. The update to this functionality introduced by CVE-2018-5743 changed how BIND calculates the number of concurrent TCP clients from counting the outstanding TCP queries to counting the TCP client connections. On a server with TCP-pipelining capability, it is possible for one TCP client to send a large number of DNS requests over a single connection. Each outstanding query will be handled internally as an independent client request, thus bypassing the new TCP clients limit.

With pipelining enabled each incoming query on a TCP connection requires a similar resource allocation to a query received via UDP or via TCP without pipelining enabled. A client using a TCP-pipelined connection to a server could consume more resources than the server has been provisioned to handle. When a TCP connection with a large number of pipelined queries is closed, the load on the server releasing these multiple resources can cause it to become unresponsive, even for queries that can be answered authoritatively or from cache.

Affected Versions:
BIND 9.11.6-P1 - 9.11.12, 9.12.4-P1 - 9.12.4-P2, 9.14.1 - 9.14.7 and 9.11.5-S6 - 9.11.12-S1. Also affects all releases in the 9.15 development branch.

Update to version 9.11.13, 9.14.8, 9.15.6, 9.11.13-S1 or later.

NIST (National Institute of Standards and Technology) NVD (National Vulnerability Database)


CVSS Score
Denial of Service

Free Vulnerability Scanning, Assessment and Management

Mageni's Platform is packed with all the features you need to scan, assess and manage vulnerabilities like this - it is free, open source, lightning fast, reliable and scalable.


Frequently Asked Questions

No, you can scan concurrently as many assets as you want. Please note that you must be aware of the hardware requeriments of the platform to ensure a good performance.

No, you can add as many assest as you want. It doesn't matters if you have millions of assets, we won't charge you for that.

No. The software is completely free. We have no intention to charge you to use the software, in fact - it completely goes against our beliefs and business model.

A vulnerability is defined in the ISO 27002 standard as “A weakness of an asset or group of assets that can be exploited by one or more threats” (International Organization for Standardization, 2005)

We generate revenue by providing support and other services for customers that require a subscription so they get guaranteed support and enterprise services. To use Mageni's Platform is completely free, with no limits at all.

Yes. Mageni understands that there are professionals and businesses that need commercial support so Mageni provides an active support subscription with everything needed to run Mageni's Platform reliably and securely. More than software, it's access to security experts, knowledge resources, security updates, and support tools you can't get anywhere else. The subscription includes:

  • Ongoing delivery
    • Patches
    • Bug fixes
    • Updates
    • Upgrades
  • Technical support
    • 24/7 availability
    • Unlimited Incidents
    • Specialty-based routing
    • Multi-Channel
  • Commitments
    • Software certifications
    • Software assurance
    • SLA

No, we don't store the information of your vulnerabilities in our servers.

Vulnerability management is the process in which vulnerabilities in IT are identified and the risks of these vulnerabilities are evaluated. This evaluation leads to correcting the vulnerabilities and removing the risk or a formal risk acceptance by the management of an organization. The term vulnerability management is often confused with vulnerability scanning. Despite the fact both are related, there is an important difference between the two. Vulnerability scanning consists of using a computer program to identify vulnerabilities in networks, computer infrastructure or applications. Vulnerability management is the process surrounding vulnerability scanning, also taking into account other aspects such as risk acceptance, remediation etc. Source: "Implementing a Vulnerability Management Process". SANS Institute.

I am ready to start scanning for vulnerabilities