Denial of service in ISC BIND



Published: 2019-11-21
Risk Medium
Patch available YES
Number of vulnerabilities 1
CVE-ID CVE-2019-6477
CWE-ID CWE-399
Exploitation vector Network
Public exploit N/A
Vulnerable software
Subscribe
ISC BIND
Server applications / DNS servers

Vendor ISC

Security Bulletin

This security bulletin contains one medium risk vulnerability.

1) Resource management error

EUVDB-ID: #VU22894

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-6477

CWE-ID: CWE-399 - Resource Management Errors

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to incorrect implementation of TCP-pipelining feature in ISC BIND, aimed to limit the number of concurrent connections and protect the server from denial of service attacks. A remote attacker can initiate a TCP-pipelined connection with multiple queries that consume more resources than the server has been provisioned to handle and crash the server, when closing the connection.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

ISC BIND: 9.11.5-S6 - 9.15.5

External links

http://kb.isc.org/docs/cve-2019-6477


Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.



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