AlmaLinux 9.2 [TuxCare] Security Update: python3-unbound / unbound / unbound-devel / unbound-libs Multiple Vulnerabilities (ALMALINUX9.2:CLSA-2026:1780509244)

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

include('compat.inc');

if (description)
{
  script_id(359664);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/01");

  script_cve_id(
    "CVE-2025-11411",
    "CVE-2026-32792",
    "CVE-2026-44390",
    "CVE-2026-44608"
  );
  script_xref(name:"CLSA", value:"2026:1780509244");

  script_name(english:"AlmaLinux 9.2 [TuxCare] Security Update: python3-unbound / unbound / unbound-devel / unbound-libs Multiple Vulnerabilities (ALMALINUX9.2:CLSA-2026:1780509244)");

  script_set_attribute(attribute:"synopsis", value:
"The AlmaLinux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The AlmaLinux 9.2 host has packages installed that are affected by multiple vulnerabilities as referenced in the TuxCare
ALMALINUX9.2:CLSA-2026:1780509244 advisory.

  - NLnet Labs Unbound up to and including version 1.24.1 is vulnerable to possible domain hijack attacks.
    Promiscuous NS RRSets that complement positive DNS replies in the authority section can be used to trick
    resolvers to update their delegation information for the zone. Usually these RRSets are used to update the
    resolver's knowledge of the zone's name servers. A malicious actor can exploit the possible poisonous
    effect by injecting NS RRSets (and possibly their respective address records) in a reply. This could be
    done for example by trying to spoof a packet or fragmentation attacks. Unbound would then proceed to
    update the NS RRSet data it already has since the new data has enough trust for it, i.e., in-zone data for
    the delegation point. Unbound 1.24.1 includes a fix that scrubs unsolicited NS RRSets (and their
    respective address records) from replies mitigating the possible poison effect. Unbound 1.24.2 includes an
    additional fix that scrubs unsolicited NS RRSets (and their respective address records) from YXDOMAIN and
    non-referral nodata replies, further mitigating the possible poison effect. (CVE-2025-11411)

  - NLnet Labs Unbound 1.6.2 up to and including version 1.25.0 has a denial of service vulnerability when
    compiled with DNSCrypt support ('--enable-dnscrypt'). A bad DNSCrypt query could underflow Unbound's
    DNSCrypt packet reading procedure that may lead to heap overflow. A malicious actor can exploit the
    vulnerability with a single bad DNSCrypt query that its decrypted plaintext consists entirely of '0x00'
    bytes and does not contain the expected '0x80' marker. Unbound would then start reading more bytes than
    necessary until it finds a non-'0x00' byte. Based on the underlying memory allocator and the memory
    layout, it could lead to heap overflow while reading followed by a crash. Likelihood of a crash is low,
    since it relies heavily on the underlying memory allocator and the memory layout. If the heap overflow
    does not happen, Unbound's later packet checks will deny the packet. Unbound 1.25.1 contains a patch with
    a fix to bound reading in the given buffer space. (CVE-2026-32792)

  - NLnet Labs Unbound up to and including version 1.25.0 has a vulnerability when handling replies with very
    large RRsets that Unbound needs to perform name compression for. Malicious upstream responses with very
    large RRsets with records that don't share a suffix above the root can cause Unbound to spend a
    considerable time applying name compression to downstream replies. This can lead to degraded performance
    and eventually denial of service in well orchestrated attacks. An adversary can exploit the vulnerability
    by querying Unbound for the specially crafted contents of a malicious zone with very large RRsets. Before
    Unbound replies to the query it will try to apply name compression which was an unbounded operation that
    could lock the CPU until the whole packet was complete. A compression limit was introduced in 1.21.1 for
    this but it didn't account for the case where records would not share any suffix above the root. That
    causes Unbound to go in a different code path because of the compression tree lookup failure and
    eventually not increment the compression counter for those operations. Unbound 1.25.1 contains a patch
    with a fix that increments the compression counter regardless of the compression tree lookup. This is a
    complement fix to CVE-2024-8508. (CVE-2026-44390)

  - NLnet Labs Unbound 1.14.0 up to and including version 1.25.0 has a locking inconsistency vulnerability
    that when certain conditions are met (multi-threaded, RPZ XFR reload, RPZ zone with 'rpz-nsip'/'rpz-
    nsdname' triggers) it could result in heap use-after-free and eventual crash. An adversary can exploit the
    vulnerability if conditions are first met on a vulnerable Unbound, i.e., multi-threaded, an RPZ zone with
    'rpz-nsip'/'rpz-nsdname' triggers and an ongoing XFR for that RPZ zone. Local RPZ files do not trigger the
    vulnerability. If the timing is right and an XFR happens at the same time another thread needs to read
    that RPZ zone, the reader may not hold the lock long enough and the thread applying the XFR may free
    objects that the reader is about to walk causing the use-after-free. Unbound 1.25.1 contains a patch with
    a fix to the locking code. (CVE-2026-44608)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  # https://security.tuxcare.com/csaf/v2/els_os/almalinux9.2esu/advisories/2026/clsa-2026_1780509244.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?59d9063c");
  script_set_attribute(attribute:"see_also", value:"https://cve.tuxcare.com/els/releases/CLSA-2026:1780509244");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages based on the guidance in TuxCare advisory ALMALINUX9.2:CLSA-2026:1780509244.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/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:H/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:"cvss4_vector", value:"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:U");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-44608");

  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:"Moderate");

  script_set_attribute(attribute:"vuln_publication_date", value:"2025/10/22");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/06/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/01");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  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:"^9.2([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'AlmaLinux 9.2', '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 (cpu !~ "^i[3-6]86$" && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'AlmaLinux', cpu);


var constraints = [
  {
    'release': '9',
    'sp': '2',
    'pkgs': [
      {'reference':'python3-unbound-1.16.2-3.el9_2.tuxcare.els8', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'unbound-1.16.2-3.el9_2.tuxcare.els8', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'unbound-devel-1.16.2-3.el9_2.tuxcare.els8', 'sp':'2', 'cpu':'i686', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'unbound-devel-1.16.2-3.el9_2.tuxcare.els8', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'unbound-libs-1.16.2-3.el9_2.tuxcare.els8', 'sp':'2', 'cpu':'i686', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'unbound-libs-1.16.2-3.el9_2.tuxcare.els8', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', '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_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, 'python3-unbound / unbound / unbound-devel / unbound-libs');
}