Amazon Linux 2 : samba, --advisory ALAS2-2026-3886 (ALAS-2026-3886)

#%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-2026-3886.
##

include('compat.inc');

if (description)
{
  script_id(341891);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/31");

  script_cve_id(
    "CVE-2026-6949",
    "CVE-2026-15779",
    "CVE-2026-58222",
    "CVE-2026-58224"
  );
  script_xref(name:"IAVA", value:"2026-A-0794");

  script_name(english:"Amazon Linux 2 : samba, --advisory ALAS2-2026-3886 (ALAS-2026-3886)");

  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 samba installed on the remote host is prior to 4.10.16-24. It is, therefore, affected by multiple
vulnerabilities as referenced in the ALAS2-2026-3886 advisory.

    A flaw was found in samba's pam_winbind. When mkhomedir is enabled, pam_winbind chowns the target
    account's home directory without validating the path is not a critical system directory such as /. On
    affected systems, accounts with / as their home directory (a common default for system accounts) can have
    this triggered not only by root, but by a non-root user holding a narrow sudo delegation to run commands
    as that account, causing ownership of / to change and resulting in severe denial of service (SSH, sudo,
    and package-manager failures). The change does not grant write access to / (which ships with restrictive
    0555 permissions on RHEL), so the impact is availability loss rather than further privilege escalation.
    (CVE-2026-15779)

    Samba AD LDAP Compare filter injection and trusted-request confusion disclose protected attributes
    (CVE-2026-58222)

    The CTDB protocol has bounds checking issues

    NOTE: https://www.samba.org/samba/security/CVE-2026-58224-advisory.html (CVE-2026-58224)

    TSIG packet with name compression can crash DNS (CVE-2026-6949)

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/ALAS2-2026-3886.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-2026-15779.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-58222.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-58224.html");
  script_set_attribute(attribute:"see_also", value:"https://explore.alas.aws.amazon.com/CVE-2026-6949.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update samba' or
  or 'yum update --advisory ALAS2-2026-3886' to update your system.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/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:L/PR:L/UI:N/S:U/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-2026-58222");

  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:"2026/07/15");
  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:ctdb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:ctdb-tests");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:libsmbclient");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:libsmbclient-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:libwbclient");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:libwbclient-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-client");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-client-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-common-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-common-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-dc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-dc-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-krb5-printing");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-pidl");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-python");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-python-test");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-test");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-test-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-vfs-glusterfs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-winbind");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-winbind-clients");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-winbind-krb5-locator");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:samba-winbind-modules");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux:2");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_set_attribute(attribute:"stig_severity", value:"I");
  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':'ctdb-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ctdb-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ctdb-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ctdb-tests-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ctdb-tests-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'ctdb-tests-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libsmbclient-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libsmbclient-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libsmbclient-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libsmbclient-devel-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libsmbclient-devel-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libsmbclient-devel-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libwbclient-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libwbclient-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libwbclient-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libwbclient-devel-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libwbclient-devel-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'libwbclient-devel-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-client-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-client-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-client-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-client-libs-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-client-libs-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-client-libs-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-common-4.10.16-24.amzn2.0.9', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-common-libs-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-common-libs-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-common-libs-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-common-tools-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-common-tools-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-common-tools-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-dc-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-dc-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-dc-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-dc-libs-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-dc-libs-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-dc-libs-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-debuginfo-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-debuginfo-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-debuginfo-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-devel-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-devel-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-devel-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-krb5-printing-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-krb5-printing-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-krb5-printing-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-libs-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-libs-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-libs-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-pidl-4.10.16-24.amzn2.0.9', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-python-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-python-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-python-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-python-test-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-python-test-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-python-test-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-test-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-test-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-test-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-test-libs-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-test-libs-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-test-libs-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-vfs-glusterfs-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-winbind-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-winbind-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-winbind-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-winbind-clients-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-winbind-clients-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-winbind-clients-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-winbind-krb5-locator-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-winbind-krb5-locator-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-winbind-krb5-locator-4.10.16-24.amzn2.0.9', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-winbind-modules-4.10.16-24.amzn2.0.9', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-winbind-modules-4.10.16-24.amzn2.0.9', 'cpu':'i686', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'samba-winbind-modules-4.10.16-24.amzn2.0.9', '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, "ctdb / ctdb-tests / libsmbclient / etc");
}