Ubuntu 20.04 LTS : Bind vulnerabilities (USN-6642-1)

high Nessus Plugin ID 190715

Synopsis

The remote Ubuntu host is missing one or more security updates.

Description

The remote Ubuntu 20.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-6642-1 advisory.

- The DNS message parsing code in `named` includes a section whose computational complexity is overly high.
It does not cause problems for typical DNS traffic, but crafted queries and responses may cause excessive CPU load on the affected `named` instance by exploiting this flaw. This issue affects both authoritative servers and recursive resolvers. This issue affects BIND 9 versions 9.0.0 through 9.16.45, 9.18.0 through 9.18.21, 9.19.0 through 9.19.19, 9.9.3-S1 through 9.11.37-S1, 9.16.8-S1 through 9.16.45-S1, and 9.18.11-S1 through 9.18.21-S1. (CVE-2023-4408)

- Certain DNSSEC aspects of the DNS protocol (in RFC 4033, 4034, 4035, 6840, and related RFCs) allow remote attackers to cause a denial of service (CPU consumption) via one or more DNSSEC responses, aka the KeyTrap issue. One of the concerns is that, when there is a zone with many DNSKEY and RRSIG records, the protocol specification implies that an algorithm must evaluate all combinations of DNSKEY and RRSIG records. (CVE-2023-50387)

- The Closest Encloser Proof aspect of the DNS protocol (in RFC 5155 when RFC 9276 guidance is skipped) allows remote attackers to cause a denial of service (CPU consumption for SHA-1 computations) via DNSSEC responses in a random subdomain attack, aka the NSEC3 issue. The RFC 5155 specification implies that an algorithm must perform thousands of iterations of a hash function in certain situations. (CVE-2023-50868)

- A flaw in query-handling code can cause `named` to exit prematurely with an assertion failure when: - `nxdomain-redirect <domain>;` is configured, and - the resolver receives a PTR query for an RFC 1918 address that would normally result in an authoritative NXDOMAIN response. This issue affects BIND 9 versions 9.12.0 through 9.16.45, 9.18.0 through 9.18.21, 9.19.0 through 9.19.19, 9.16.8-S1 through 9.16.45-S1, and 9.18.11-S1 through 9.18.21-S1. (CVE-2023-5517)

- To keep its cache database efficient, `named` running as a recursive resolver occasionally attempts to clean up the database. It uses several methods, including some that are asynchronous: a small chunk of memory pointing to the cache element that can be cleaned up is first allocated and then queued for later processing. It was discovered that if the resolver is continuously processing query patterns triggering this type of cache-database maintenance, `named` may not be able to handle the cleanup events in a timely manner. This in turn enables the list of queued cleanup events to grow infinitely large over time, allowing the configured `max-cache-size` limit to be significantly exceeded. This issue affects BIND 9 versions 9.16.0 through 9.16.45 and 9.16.8-S1 through 9.16.45-S1. (CVE-2023-6516)

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

Solution

Update the affected packages.

See Also

https://ubuntu.com/security/notices/USN-6642-1

Plugin Details

Severity: High

ID: 190715

File Name: ubuntu_USN-6642-1.nasl

Version: 1.0

Type: local

Agent: unix

Published: 2/19/2024

Updated: 2/19/2024

Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.1

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

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

CVSS Score Source: CVE-2023-6516

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

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

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:20.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:bind9, p-cpe:/a:canonical:ubuntu_linux:bind9-dnsutils, p-cpe:/a:canonical:ubuntu_linux:bind9-host, p-cpe:/a:canonical:ubuntu_linux:bind9-libs, p-cpe:/a:canonical:ubuntu_linux:bind9-utils, p-cpe:/a:canonical:ubuntu_linux:bind9utils, p-cpe:/a:canonical:ubuntu_linux:dnsutils

Required KB Items: Host/cpu, Host/Ubuntu, Host/Ubuntu/release, Host/Debian/dpkg-l

Exploit Ease: No known exploits are available

Patch Publication Date: 2/19/2024

Vulnerability Publication Date: 2/13/2024

Reference Information

CVE: CVE-2023-4408, CVE-2023-50387, CVE-2023-50868, CVE-2023-5517, CVE-2023-6516

IAVA: 2024-A-0103

USN: 6642-1