Denial of service in ISC Bind

1) Race condition

EUVDB-ID: #VU21568

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-2019-6471

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Exploit availability: No

Description

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

The vulnerability exists due to a race condition when processing DNS requests in dispatch.c. A remote attacker can send specially crafted DNS packets to the affected daemon, trigger a REQUIRE assertion failure and crash the DNS server.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

ISC BIND: 9.11.0 - 9.14.2

External links

http://kb.isc.org/docs/cve-2019-6471

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.