Amazon Linux 2 : 389-ds-base (ALAS-2026-4003)

#%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-2026-4003.
##

include('compat.inc');

if (description)
{
  script_id(371789);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/24");

  script_cve_id("CVE-2026-86344", "CVE-2026-86345");

  script_name(english:"Amazon Linux 2 : 389-ds-base (ALAS-2026-4003)");

  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 389-ds-base installed on the remote host is prior to 1.3.10.2-17. It is, therefore, affected by multiple
vulnerabilities as referenced in the ALAS2-2026-4003 advisory.

    A flaw was found in 389-ds-base. An unauthenticated remote attacker can send a complete LDAP operation
    followed by the first bytes of an incomplete LDAPMessage on the same connection, causing the server to
    hand that connection to a second worker thread before the first worker's result is flushed. The second
    worker blocks until nsslapd-ioblocktimeout while holding the connection mutex, preventing delivery of the
    completed operation's result. Repeating this across a small number of connections proportional to the
    configured worker-thread pool size exhausts the entire pool under default configuration, denying service
    to all clients (anonymous and authenticated, plaintext and TLS) for as long as the attacker maintains the
    connections. (CVE-2026-86344)

    A flaw was found in 389-ds-base. The server does not discard plaintext bytes already buffered from a
    client connection when negotiating StartTLS, allowing an on-path attacker to inject a crafted LDAP message
    that is processed after the TLS upgrade and whose response is delivered to the client in place of the
    client's own pending operation's response, due to messageID collision. This can cause a client application
    to treat a failed authentication (bind) attempt as successful. (CVE-2026-86345)

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/ALAS2-2026-4003.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-2026-86344.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-86345.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update 389-ds-base' or
  or 'yum update --advisory ALAS2-2026-4003' to update your system.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/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-2026-86345");

  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:"2026/10/01");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/24");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/24");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:389-ds-base");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:389-ds-base-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:389-ds-base-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:389-ds-base-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:389-ds-base-snmp");
  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_info2.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':'389-ds-base-1.3.10.2-17.amzn2.0.14', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'389-ds-base-1.3.10.2-17.amzn2.0.14', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'389-ds-base-1.3.10.2-17.amzn2.0.14', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'389-ds-base-debuginfo-1.3.10.2-17.amzn2.0.14', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'389-ds-base-debuginfo-1.3.10.2-17.amzn2.0.14', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'389-ds-base-debuginfo-1.3.10.2-17.amzn2.0.14', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'389-ds-base-devel-1.3.10.2-17.amzn2.0.14', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'389-ds-base-devel-1.3.10.2-17.amzn2.0.14', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'389-ds-base-devel-1.3.10.2-17.amzn2.0.14', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'389-ds-base-libs-1.3.10.2-17.amzn2.0.14', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'389-ds-base-libs-1.3.10.2-17.amzn2.0.14', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'389-ds-base-libs-1.3.10.2-17.amzn2.0.14', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'389-ds-base-snmp-1.3.10.2-17.amzn2.0.14', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'389-ds-base-snmp-1.3.10.2-17.amzn2.0.14', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'389-ds-base-snmp-1.3.10.2-17.amzn2.0.14', '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_HOLE,
      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, "389-ds-base / 389-ds-base-debuginfo / 389-ds-base-devel / etc");
}