Amazon Linux 2 : iscsi-initiator-utils, --advisory ALAS2-2026-3897 (ALAS-2026-3897)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux 2 Security Advisory ALAS-2026-3897.
##

include('compat.inc');

if (description)
{
  script_id(341873);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/31");

  script_cve_id(
    "CVE-2026-18724",
    "CVE-2026-18725",
    "CVE-2026-18726",
    "CVE-2026-18727",
    "CVE-2026-18728"
  );

  script_name(english:"Amazon Linux 2 : iscsi-initiator-utils, --advisory ALAS2-2026-3897 (ALAS-2026-3897)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Amazon Linux 2 host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The version of iscsi-initiator-utils installed on the remote host is prior to 6.2.0.874-7. It is, therefore, affected by
multiple vulnerabilities as referenced in the ALAS2-2026-3897 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.");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com//AL2/ALAS2-2026-3897.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/faqs.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-18724.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-18725.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-18726.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-18727.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-18728.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update iscsi-initiator-utils' or
  or 'yum update --advisory ALAS2-2026-3897' to update your system.");
  script_set_cvss_base_vector("CVSS2#AV:A/AC:L/Au:N/C:N/I:N/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-18728");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/08/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/31");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/31");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:iscsi-initiator-utils");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:iscsi-initiator-utils-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:iscsi-initiator-utils-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:iscsi-initiator-utils-iscsiuio");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux:2");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Amazon Linux Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/AmazonLinux/release", "Host/AmazonLinux/rpm-list");

  exit(0);
}

include("rpm2.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);

var alas_release = get_kb_item("Host/AmazonLinux/release");
if (isnull(alas_release) || !strlen(alas_release)) audit(AUDIT_OS_NOT, "Amazon Linux");
var os_ver = pregmatch(pattern: "^AL(A|\d+|-\d+)", string:alas_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Amazon Linux");
os_ver = os_ver[1];
if (os_ver != "2")
{
  if (os_ver == 'A') os_ver = 'AMI';
  audit(AUDIT_OS_NOT, "Amazon Linux 2", "Amazon Linux " + os_ver);
}

if (!get_kb_item("Host/AmazonLinux/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

var pkgs = [
    {'reference':'iscsi-initiator-utils-6.2.0.874-7.amzn2.0.2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'iscsi-initiator-utils-6.2.0.874-7.amzn2.0.2', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'iscsi-initiator-utils-6.2.0.874-7.amzn2.0.2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'iscsi-initiator-utils-debuginfo-6.2.0.874-7.amzn2.0.2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'iscsi-initiator-utils-debuginfo-6.2.0.874-7.amzn2.0.2', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'iscsi-initiator-utils-debuginfo-6.2.0.874-7.amzn2.0.2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'iscsi-initiator-utils-devel-6.2.0.874-7.amzn2.0.2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'iscsi-initiator-utils-devel-6.2.0.874-7.amzn2.0.2', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'iscsi-initiator-utils-devel-6.2.0.874-7.amzn2.0.2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'iscsi-initiator-utils-iscsiuio-6.2.0.874-7.amzn2.0.2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'iscsi-initiator-utils-iscsiuio-6.2.0.874-7.amzn2.0.2', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'iscsi-initiator-utils-iscsiuio-6.2.0.874-7.amzn2.0.2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE}
];

var flag = 0;
foreach var package_array ( pkgs ) {
  var reference = NULL;
  var _release = NULL;
  var sp = NULL;
  var _cpu = NULL;
  var el_string = NULL;
  var rpm_spec_vers_cmp = NULL;
  var epoch = NULL;
  var allowmaj = NULL;
  var exists_check = NULL;
  var cves = NULL;
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (!empty_or_null(package_array['release'])) _release = package_array['release'];
  if (!empty_or_null(package_array['sp'])) sp = package_array['sp'];
  if (!empty_or_null(package_array['cpu'])) _cpu = package_array['cpu'];
  if (!empty_or_null(package_array['el_string'])) el_string = package_array['el_string'];
  if (!empty_or_null(package_array['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = package_array['rpm_spec_vers_cmp'];
  if (!empty_or_null(package_array['epoch'])) epoch = package_array['epoch'];
  if (!empty_or_null(package_array['allowmaj'])) allowmaj = package_array['allowmaj'];
  if (!empty_or_null(package_array['exists_check'])) exists_check = package_array['exists_check'];
  if (!empty_or_null(package_array['cves'])) cves = package_array['cves'];
  if (reference && _release && (!exists_check || rpm_exists(release:_release, rpm:exists_check))) {
    if (rpm_check(release:_release, sp:sp, cpu:_cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj, cves:cves)) flag++;
  }
}

if (flag)
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_WARNING,
      extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "iscsi-initiator-utils / iscsi-initiator-utils-debuginfo / iscsi-initiator-utils-devel / etc");
}