ISC BIND GSS-TSIG SPNEGO Buffer Overflow (CVE-2021-25216)

critical Nessus Plugin ID 149210
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Synopsis

The remote name server is affected by a buffer overflow vulnerability.

Description

According to its self-reported version, the ISC Bind present on the remote host is affected by a buffer overflow vulnerability:

- GSS-TSIG is an extension to the TSIG protocol which is intended to support the secure exchange of keys for use in verifying the authenticity of communications between parties on a network. SPNEGO is a negotiation mechanism used by GSSAPI, the application protocol interface for GSS-TSIG.
BIND servers are vulnerable if they are running an affected version and are configured to use GSS-TSIG features. n a configuration which uses BIND's default settings the vulnerable code path is not exposed, but a server can be rendered vulnerable by explicitly setting values for the tkey-gssapi-keytab or tkey-gssapi-credential configuration options. Although the default configuration is not vulnerable, GSS-TSIG is frequently used in networks where BIND is integrated with Samba, as well as in mixed-server environments that combine BIND servers with Active Directory domain controllers. For servers that meet these conditions, the ISC SPNEGO implementation is vulnerable to various attacks, depending on the CPU architecture for which BIND was built.

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

Solution

Upgrade to the patched release most closely related to your current version of BIND.

See Also

https://kb.isc.org/v1/docs/CVE-2021-25216

Plugin Details

Severity: Critical

ID: 149210

File Name: bind9_91712_cve-2021-25216.nasl

Version: 1.7

Type: remote

Family: DNS

Published: 4/30/2021

Updated: 5/13/2021

Dependencies: bind_version.nasl

Configuration: Enable paranoid mode

Risk Information

CVSS Score Source: CVE-2021-25216

VPR

Risk Factor: High

Score: 7.4

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

Vector: AV:N/AC:M/Au:N/C:P/I:P/A:P

Temporal Vector: E:U/RL:OF/RC:C

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

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

Temporal Vector: 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: 4/28/2021

Vulnerability Publication Date: 4/28/2021

Reference Information

CVE: CVE-2021-25216

IAVA: 2021-A-0206