Vulnerability identifier: #VU48663

Vulnerability risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: N/A

CWE-ID: CWE-476

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
ISC BIND
Server applications / DNS servers

Vendor: ISC

Description

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

The vulnerability exists due to a NULL pointer dereference error. After a Negative Trust Anchor (NTA) is added, BIND performs periodic checks to see if it is still necessary. If BIND encountered a failure while creating a query to perform such a check, it attempted to dereference a NULL pointer, resulting in a crash. A remote user can pass specially crafted data to the application and perform a denial of service (DoS) attack.

Mitigation
Install update from vendor's website.

Vulnerable software versions

ISC BIND: 9.11.0 - 9.11.24-S1

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External links
http://www.slackware.com/security/viewer.php?l=slackware-security&y=2020&m=slackware-security.434041

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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