ISC BIND 9.3.0 < 9.11.36 / 9.9.3-S1 < 9.11.36-S1 / 9.12.0 < 9.16.22 / 9.16.8-S1 < 9.16.22-S1 / 9.17.0 < 9.17.19 Vulnerability (CVE-2021-25219)

medium Nessus Plugin ID 154662


The remote name server is affected by a vulnerability vulnerability.


The version of ISC BIND installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the CVE-2021-25219 advisory.

- In BIND 9.3.0 -> 9.11.35, 9.12.0 -> 9.16.21, and versions 9.9.3-S1 -> 9.11.35-S1 and 9.16.8-S1 -> 9.16.21-S1 of BIND Supported Preview Edition, as well as release versions 9.17.0 -> 9.17.18 of the BIND 9.17 development branch, exploitation of broken authoritative servers using a flaw in response processing can cause degradation in BIND resolver performance. The way the lame cache is currently designed makes it possible for its internal data structures to grow almost infinitely, which may cause significant delays in client query processing. (CVE-2021-25219)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.


Upgrade to ISC BIND version 9.11.36 / 9.11.36-S1 / 9.16.22 / 9.16.22-S1 / 9.17.19 or later.

See Also

Plugin Details

Severity: Medium

ID: 154662

File Name: bind9_91719.nasl

Version: 1.5

Type: remote

Family: DNS

Published: 10/28/2021

Updated: 9/27/2022

Configuration: Enable paranoid mode

Risk Information


Risk Factor: Low

Score: 2.2


Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P

CVSS Score Source: CVE-2021-25219


Risk Factor: Medium

Base Score: 5.3

Temporal Score: 4.6

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:isc:bind

Required KB Items: bind/version, Settings/ParanoidReport

Exploit Ease: No known exploits are available

Patch Publication Date: 10/27/2021

Vulnerability Publication Date: 10/27/2021

Reference Information

CVE: CVE-2021-25219

IAVA: 2021-A-0525-S