Amazon Linux 2023 : iscsi-initiator-utils, iscsi-initiator-utils-devel, iscsi-initiator-utils-iscsiuio (ALAS2023-2026-2120)

medium Nessus Plugin ID 341851

Synopsis

The remote Amazon Linux 2023 host is missing a security update.

Description

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2026-2120 advisory.

open-iscsi: open-iscsi: Stack buffer overflow in idbm record parsing (CVE-2026-18724)

open-iscsi: open-iscsi: Out-of-bounds access in iscsiuio ICMPv6 echo handling (CVE-2026-18725)

A flaw was found in open-iscsi. This vulnerability allows a remote attacker on the same local network segment to cause a Denial of Service (DoS) in the iscsiuio daemon. By sending a specially crafted Internet Control Message Protocol version 6 (ICMPv6) Router Advertisement with a zero-length option, the attacker can trigger an infinite loop. This leads to sustained CPU usage, rendering the daemon unresponsive and impacting system availability. A secondary risk of out-of-bounds reads exists with a short IPv6 payload, though no memory corruption or data exposure has been confirmed. (CVE-2026-18726)

A flaw was found in open-iscsi's iscsiuio component. This vulnerability involves an integer underflow and out-of-bounds read during Dynamic Host Configuration Protocol for IPv6 (DHCPv6) packet parsing.
Specifically, crafted DHCPv6 Advertise traffic with a short User Datagram Protocol (UDP) length can cause the DHCPv6 payload length to underflow. An unauthenticated attacker on an adjacent network segment can exploit this by sending specially crafted IPv6 UDP traffic while the client is in an active DHCPv6 exchange, leading to a denial of service due to a process crash or service disruption. (CVE-2026-18727)

A flaw was found in open-iscsi. An integer underflow vulnerability in the `iscsiuio` component, specifically during IPv4 Dynamic Host Configuration Protocol (DHCP) parsing, allows a remote attacker on the same local network segment to cause a denial of service. By sending a specially crafted IPv4/UDP DHCP reply, the attacker can trigger an out-of-bounds read, leading to the `iscsiuio` process crashing. This issue affects systems where `iscsiuio` is actively handling IPv4 DHCP traffic. (CVE-2026-18728)

Tenable has extracted the preceding description block directly from the tested product 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

Run 'dnf update iscsi-initiator-utils --releasever 2023.12.20260831' or or 'dnf update --advisory ALAS2023-2026-2120 --releasever 2023.12.20260831' to update your system.

Plugin Details

Severity: Medium

ID: 341851

File Name: al2023_ALAS2023-2026-2120.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 8/31/2026

Updated: 8/31/2026

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Nessus Agent, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.61

CVSS v2

Risk Factor: Medium

Base Score: 6.1

Temporal Score: 4.5

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

CVSS Score Source: CVE-2026-18728

CVSS v3

Risk Factor: Medium

Base Score: 6.5

Temporal Score: 5.7

Vector: CVSS:3.0/AV:A/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:amazon:linux:2023, p-cpe:/a:amazon:linux:iscsi-initiator-utils-debuginfo, p-cpe:/a:amazon:linux:iscsi-initiator-utils-debugsource, p-cpe:/a:amazon:linux:iscsi-initiator-utils-devel, p-cpe:/a:amazon:linux:iscsi-initiator-utils-iscsiuio-debuginfo, p-cpe:/a:amazon:linux:iscsi-initiator-utils-iscsiuio, p-cpe:/a:amazon:linux:iscsi-initiator-utils, p-cpe:/a:amazon:linux:python3-iscsi-initiator-utils-debuginfo, p-cpe:/a:amazon:linux:python3-iscsi-initiator-utils

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 8/31/2026

Vulnerability Publication Date: 8/12/2026

Reference Information

CVE: CVE-2026-18724, CVE-2026-18725, CVE-2026-18726, CVE-2026-18727, CVE-2026-18728

Detections

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