Amazon Linux 2 : ipa, --advisory ALAS2-2026-3877 (ALAS-2026-3877)

#%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-2026-3877.
##

include('compat.inc');

if (description)
{
  script_id(339665);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/26");

  script_cve_id("CVE-2026-11861", "CVE-2026-13097");

  script_name(english:"Amazon Linux 2 : ipa, --advisory ALAS2-2026-3877 (ALAS-2026-3877)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Amazon Linux 2 host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2026-3877 advisory.

    A flaw was found in FreeIPA. When a trust relationship is configured between FreeIPA and Active Directory,
    Active Directory users can bypass authentication for FreeIPA services, including the portal, SMB server,
    and LDAP directory. This is possible by impersonating a client name in the Ticket Granting Service (TGS)
    due to FreeIPA services not verifying Privilege Attribute Certificate (PAC) certificates. This
    vulnerability could allow an authenticated Active Directory user to escalate their privileges within the
    FreeIPA domain. (CVE-2026-11861)

    A privilege escalation flaw was found in FreeIPA. The uniqueness constraint enforced on Kerberos principal
    name attributes in the 389-ds directory server does not properly account for equivalent representations of
    the same principal name, allowing a user with sufficient LDAP write privileges to create a service
    principal that impersonates an existing privileged one. This can lead to unauthorized acquisition of
    Kerberos service tickets for sensitive services, potentially resulting in full domain compromise.
    (CVE-2026-13097)

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/ALAS2-2026-3877.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-2026-11861.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-13097.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update ipa' or
  or 'yum update --advisory ALAS2-2026-3877' to update your system.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-11861");

  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:"2026/08/20");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/25");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/26");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ipa-client");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ipa-client-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ipa-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ipa-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ipa-python-compat");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ipa-server");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ipa-server-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ipa-server-dns");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ipa-server-trust-ad");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:python2-ipaclient");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:python2-ipalib");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:python2-ipaserver");
  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':'ipa-client-4.6.8-5.amzn2.17.5', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ipa-client-4.6.8-5.amzn2.17.5', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ipa-client-4.6.8-5.amzn2.17.5', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ipa-client-common-4.6.8-5.amzn2.17.5', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ipa-common-4.6.8-5.amzn2.17.5', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ipa-debuginfo-4.6.8-5.amzn2.17.5', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ipa-debuginfo-4.6.8-5.amzn2.17.5', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ipa-debuginfo-4.6.8-5.amzn2.17.5', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ipa-python-compat-4.6.8-5.amzn2.17.5', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ipa-server-4.6.8-5.amzn2.17.5', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ipa-server-4.6.8-5.amzn2.17.5', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ipa-server-4.6.8-5.amzn2.17.5', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ipa-server-common-4.6.8-5.amzn2.17.5', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ipa-server-dns-4.6.8-5.amzn2.17.5', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ipa-server-trust-ad-4.6.8-5.amzn2.17.5', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ipa-server-trust-ad-4.6.8-5.amzn2.17.5', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ipa-server-trust-ad-4.6.8-5.amzn2.17.5', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python2-ipaclient-4.6.8-5.amzn2.17.5', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python2-ipalib-4.6.8-5.amzn2.17.5', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python2-ipaserver-4.6.8-5.amzn2.17.5', '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, "ipa-client / ipa-client-common / ipa-common / etc");
}