AlmaLinux 9.2 [TuxCare] Security Update: tigervnc / tigervnc-icons / tigervnc-license / tigervnc-selinux / etc Multiple Vulnerabilities (ALMALINUX9.2:CLSA-2025:1743071343)

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

include('compat.inc');

if (description)
{
  script_id(352021);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/30");

  script_cve_id(
    "CVE-2025-26594",
    "CVE-2025-26596",
    "CVE-2025-26597",
    "CVE-2025-26598",
    "CVE-2025-26599",
    "CVE-2025-26600",
    "CVE-2025-26601"
  );
  script_xref(name:"CLSA", value:"2025:1743071343");

  script_name(english:"AlmaLinux 9.2 [TuxCare] Security Update: tigervnc / tigervnc-icons / tigervnc-license / tigervnc-selinux / etc Multiple Vulnerabilities (ALMALINUX9.2:CLSA-2025:1743071343)");

  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-2025:1743071343 advisory.

  - A use-after-free flaw was found in X.Org and Xwayland. The root cursor is referenced in the X server as a
    global variable. If a client frees the root cursor, the internal reference points to freed memory and
    causes a use-after-free. (CVE-2025-26594)

  - A heap overflow flaw was found in X.Org and Xwayland. The computation of the length in XkbSizeKeySyms()
    differs from what is written in XkbWriteKeySyms(), which may lead to a heap-based buffer overflow.
    (CVE-2025-26596)

  - A buffer overflow flaw was found in X.Org and Xwayland. If XkbChangeTypesOfKey() is called with a 0 group,
    it will resize the key symbols table to 0 but leave the key actions unchanged. If the same function is
    later called with a non-zero value of groups, this will cause a buffer overflow because the key actions
    are of the wrong size. (CVE-2025-26597)

  - An out-of-bounds write flaw was found in X.Org and Xwayland. The function GetBarrierDevice() searches for
    the pointer device based on its device ID and returns the matching value, or supposedly NULL, if no match
    was found. However, the code will return the last element of the list if no matching device ID is found,
    which can lead to out-of-bounds memory access. (CVE-2025-26598)

  - An access to an uninitialized pointer flaw was found in X.Org and Xwayland. The function
    compCheckRedirect() may fail if it cannot allocate the backing pixmap. In that case, compRedirectWindow()
    will return a BadAlloc error without validating the window tree marked just before, which leaves the
    validated data partly initialized and the use of an uninitialized pointer later. (CVE-2025-26599)

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/2025/clsa-2025_1743071343.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?032ae0cb");
  script_set_attribute(attribute:"see_also", value:"https://cve.tuxcare.com/els/releases/CLSA-2025:1743071343");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages based on the guidance in TuxCare advisory ALMALINUX9.2:CLSA-2025:1743071343.");
  script_set_cvss_base_vector("CVSS2#AV:L/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:L/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-2025-26601");

  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:"2025/02/18");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/03/27");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/30");

  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 ('x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'AlmaLinux', cpu);


var constraints = [
  {
    'release': '9',
    'sp': '2',
    'pkgs': [
      {'reference':'tigervnc-1.12.0-13.el9_2.tuxcare.els8', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-icons-1.12.0-13.el9_2.tuxcare.els8', 'sp':'2', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-license-1.12.0-13.el9_2.tuxcare.els8', 'sp':'2', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-selinux-1.12.0-13.el9_2.tuxcare.els8', 'sp':'2', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-server-1.12.0-13.el9_2.tuxcare.els8', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-server-minimal-1.12.0-13.el9_2.tuxcare.els8', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-server-module-1.12.0-13.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, 'tigervnc / tigervnc-icons / tigervnc-license / tigervnc-selinux / etc');
}