AlmaLinux 9.6 [TuxCare] Security Update: python3-unbound / unbound / unbound-devel / unbound-dracut / etc (ALMALINUX9.6:CLSA-2026:1791278576)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(363139);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/09");

  script_cve_id("CVE-2026-85501");
  script_xref(name:"CLSA", value:"2026:1791278576");
  script_xref(name:"IAVA", value:"2026-A-1070");

  script_name(english:"AlmaLinux 9.6 [TuxCare] Security Update: python3-unbound / unbound / unbound-devel / unbound-dracut / etc (ALMALINUX9.6:CLSA-2026:1791278576)");

  script_set_attribute(attribute:"synopsis", value:
"The AlmaLinux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The AlmaLinux 9.6 host has packages installed that are affected by a vulnerability as referenced in the TuxCare
ALMALINUX9.6:CLSA-2026:1791278576 advisory.

  - Novel vulnerabilities to launch algorithmic complexity attacks on DNSSEC have been researched under the
    term 'ReTrap'. These result in degradation of service when malicious zones are used to serve the
    algorithmic complexity vulnerabilities. NLnet Labs Unbound up to and including 1.26.0 is vulnerable to
    some of them. TagTrap, where the triple(Zone, Algo, KeyTag) matching mechanism introduces a significant
    attack vector when resolvers handle malicious responses containing numerous mismatched DNSKEY, RRSIG, and
    DS record. DelegationTrap, where constructing the chain-of-trust requires iterative validation of DNSKEY
    and DS records from the root zone downward. For deeply nested domains, this results in significant
    computational overhead. NsecTrap, where responses with excessive invalid NSEC records compel the resolver
    to validate each one. AdditionalTrap, where Unbound by default would try to DNSSEC validate the ADDITIONAL
    section as well. This can be exploited to waste validation resources by malicious users. (CVE-2026-85501)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  # https://security.tuxcare.com/csaf/v2/els_os/tuxcare9.6esu/advisories/2026/clsa-2026_1791278576.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?0e45dff9");
  script_set_attribute(attribute:"see_also", value:"https://cve.tuxcare.com/els/releases/CLSA-2026:1791278576");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages based on the guidance in TuxCare advisory ALMALINUX9.6:CLSA-2026:1791278576.");
  script_set_cvss_base_vector("CVSS2#AV:N/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:N/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-2026-85501");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/09/16");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/06");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/06");

  script_set_attribute(attribute:"plugin_type", value:"local");
  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:"Alma 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/OS/extended-third-party", "Host/local_checks_enabled", "Host/AlmaLinux/release", "Host/AlmaLinux/rpm-list", "Host/cpu");

  exit(0);
}
include('rpm2.inc');

var third_party_support = get_kb_item('Host/OS/extended-third-party');
if (empty_or_null(third_party_support) || third_party_support != 'TuxCare') exit(0, 'TuxCare support not enabled.');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_product = get_kb_item('installed_os/local/SSH/0/product');
if (isnull(os_product) || 'AlmaLinux' >!< os_product) audit(AUDIT_OS_NOT, 'AlmaLinux');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'AlmaLinux');
if (! preg(pattern:"^9.6([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'AlmaLinux 9.6', 'AlmaLinux ' + os_version);

if (!get_kb_item('Host/AlmaLinux/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('aarch64' >!< cpu && cpu !~ "^i[3-6]86$" && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'AlmaLinux', cpu);


var constraints = [
  {
    'release': '9',
    'sp': '6',
    'pkgs': [
      {'reference':'python3-unbound-1.16.2-19.el9_6.1.tuxcare.els15', 'sp':'6', 'cpu':'aarch64', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'python3-unbound-1.16.2-19.el9_6.1.tuxcare.els15', 'sp':'6', 'cpu':'i686', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'python3-unbound-1.16.2-19.el9_6.1.tuxcare.els15', 'sp':'6', 'cpu':'x86_64', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'unbound-1.16.2-19.el9_6.1.tuxcare.els15', 'sp':'6', 'cpu':'aarch64', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'unbound-1.16.2-19.el9_6.1.tuxcare.els15', 'sp':'6', 'cpu':'i686', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'unbound-1.16.2-19.el9_6.1.tuxcare.els15', 'sp':'6', 'cpu':'x86_64', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'unbound-devel-1.16.2-19.el9_6.1.tuxcare.els15', 'sp':'6', 'cpu':'aarch64', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'unbound-devel-1.16.2-19.el9_6.1.tuxcare.els15', 'sp':'6', 'cpu':'i686', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'unbound-devel-1.16.2-19.el9_6.1.tuxcare.els15', 'sp':'6', 'cpu':'x86_64', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'unbound-dracut-1.16.2-19.el9_6.1.tuxcare.els15', 'sp':'6', 'cpu':'aarch64', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'unbound-dracut-1.16.2-19.el9_6.1.tuxcare.els15', 'sp':'6', 'cpu':'i686', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'unbound-dracut-1.16.2-19.el9_6.1.tuxcare.els15', 'sp':'6', 'cpu':'x86_64', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'unbound-libs-1.16.2-19.el9_6.1.tuxcare.els15', 'sp':'6', 'cpu':'aarch64', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'unbound-libs-1.16.2-19.el9_6.1.tuxcare.els15', 'sp':'6', 'cpu':'i686', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'unbound-libs-1.16.2-19.el9_6.1.tuxcare.els15', 'sp':'6', 'cpu':'x86_64', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE}
    ]
  }
];

var os_release = get_one_kb_item('installed_os/local/SSH/0/release');
var os_sp = get_one_kb_item('Host/*/minor_release');

var flag = 0;
var reference;
var sp;
var _cpu;
var el_string;
var rpm_spec_vers_cmp;
var epoch;
var allowmaj;
var exists_check;
var cves;
foreach var constraint ( constraints ) {
  # Check that the target release is equal to the affected release
  if (!empty_or_null(constraint['release'])){
    if (constraint['release'] != os_release) continue;
  }
  if (!empty_or_null(constraint['sp'])){
    if (constraint['sp'] != os_sp) continue;
  }
  foreach var pkg ( constraint['pkgs'] ) {
    reference = NULL;
    sp = NULL;
    _cpu = NULL;
    el_string = NULL;
    rpm_spec_vers_cmp = NULL;
    epoch = NULL;
    allowmaj = NULL;
    exists_check = NULL;
    cves = NULL;
    if (!empty_or_null(pkg['reference'])) reference = pkg['reference'];
    if (!empty_or_null(pkg['sp'])) sp = pkg['sp'];
    if (!empty_or_null(pkg['cpu'])) _cpu = pkg['cpu'];
    if (!empty_or_null(pkg['el_string'])) el_string = pkg['el_string'];
    if (!empty_or_null(pkg['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = pkg['rpm_spec_vers_cmp'];
    if (!empty_or_null(pkg['epoch'])) epoch = pkg['epoch'];
    if (!empty_or_null(pkg['allowmaj'])) allowmaj = pkg['allowmaj'];
    if (!empty_or_null(pkg['exists_check'])) exists_check = pkg['exists_check'];
    if (!empty_or_null(pkg['cves'])) cves = pkg['cves'];
    if (reference &&
        ## (no known rpm to check OR known rpm_exists)
        (!exists_check || rpm_exists(rpm:exists_check)) &&
        rpm_check(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, 'python3-unbound / unbound / unbound-devel / unbound-dracut / etc');
}