Detections
Analytics
Alibaba Cloud Linux 3 : 0027: unbound (ALINUX3-SA-2024:0027)
high Nessus Plugin ID 236285
Synopsis
The remote Alibaba Cloud Linux host is missing one or more security updates.Description
The remote Alibaba Cloud Linux 3 host has packages installed that are affected by multiple vulnerabilities as referenced in the ALINUX3-SA-2024:0027 advisory.Package updates are available for Alibaba Cloud Linux 3 that fix the following vulnerabilities:
CVE-2022-3204:
A vulnerability named 'Non-Responsive Delegation Attack' (NRDelegation Attack) has been discovered in various DNS resolving software. The NRDelegation Attack works by having a malicious delegation with a considerable number of non responsive nameservers. The attack starts by querying a resolver for a record that relies on those unresponsive nameservers. The attack can cause a resolver to spend a lot of time/resources resolving records under a malicious delegation point where a considerable number of unresponsive NS records reside. It can trigger high CPU usage in some resolver implementations that continually look in the cache for resolved NS records in that delegation. This can lead to degraded performance and eventually denial of service in orchestrated attacks. Unbound does not suffer from high CPU usage, but resources are still needed for resolving the malicious delegation. Unbound will keep trying to resolve the record until hard limits are reached. Based on the nature of the attack and the replies, different limits could be reached. From version 1.16.3 on, Unbound introduces fixes for better performance when under load, by cutting opportunistic queries for nameserver discovery and DNSKEY prefetching and limiting the number of times a delegation point can issue a cache lookup for missing records.
CVE-2023-50387:
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-2023-50868:
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.
Tenable has extracted the preceding description block directly from the Alibaba Cloud Linux security advisory.
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
http://mirrors.aliyun.com/alinux/3/cve/alinux3-sa-20240027.xml
Plugin Details
Severity: High
ID: 236285
File Name: alinux3_sa_2024-0027.nasl
Version: 1.1
Type: local
Published: 5/14/2025
Updated: 5/14/2025
Supported Sensors: Nessus
Risk Information
VPR
Risk Factor: Medium
Score: 5.1
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-2023-50387
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: p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:unbound, cpe:/o:alibabacloud:alibaba_cloud_linux_3, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:unbound-libs-debuginfo, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:unbound-devel, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:python3-unbound-debuginfo, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:unbound-debuginfo, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:unbound-libs, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:python3-unbound, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:unbound-debugsource
Required KB Items: Host/local_checks_enabled, Host/cpu, Host/Alibaba/release, Host/Alibaba/rpm-list
Exploit Ease: No known exploits are available
Patch Publication Date: 4/9/2024
Vulnerability Publication Date: 8/19/2021