TencentOS Server 4: xorg-x11-server-Xwayland (TSSA-2025:0205)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Tencent Linux Security Advisory TSSA-2025:0205.
##

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(239427);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/11/20");

  script_cve_id(
    "CVE-2025-26594",
    "CVE-2025-26595",
    "CVE-2025-26596",
    "CVE-2025-26597",
    "CVE-2025-26598",
    "CVE-2025-26599",
    "CVE-2025-26600",
    "CVE-2025-26601"
  );

  script_name(english:"TencentOS Server 4: xorg-x11-server-Xwayland (TSSA-2025:0205)");

  script_set_attribute(attribute:"synopsis", value:
"The remote TencentOS Server 4 host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The version of Tencent Linux installed on the remote TencentOS Server 4 host is prior to tested version. It is,
therefore, affected by multiple vulnerabilities as referenced in the TSSA-2025:0205 advisory.

    Package updates are available for TencentOS Server 4 that fix the following vulnerabilities:

    CVE-2025-26601:
    A use-after-free flaw was found in X.Org and Xwayland. When changing an alarm, the values of the change
    mask are evaluated one after the other, changing the trigger values as requested, and eventually,
    SyncInitTrigger() is called. If one of the changes triggers an error, the function will return early, not
    adding the new sync object, possibly causing a use-after-free when the alarm eventually triggers.

    CVE-2025-26600:
    A use-after-free flaw was found in X.Org and Xwayland. When a device is removed while still frozen, the
    events queued for that device remain while the device is freed. Replaying the events will cause a use-
    after-free.

    CVE-2025-26599:
    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-2025-26598:
    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-2025-26597:
    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-2025-26596:
    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-2025-26595:
    A buffer overflow flaw was found in X.Org and Xwayland. The code in XkbVModMaskText() allocates a fixed-
    sized buffer on the stack and copies the names of the virtual modifiers to that buffer. The code fails to
    check the bounds of the buffer and would copy the data regardless of the size.

    CVE-2025-26594:
    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.

Tenable has extracted the preceding description block directly from the Tencent Linux 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://mirrors.tencent.com/tlinux/errata/tssa-20250205.xml");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  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:"vuln_publication_date", value:"2025/03/22");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/03/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/06/16");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:tencent:tencentos_server:4");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:tencent:tencentos_server:xorg-x11-server-Xwayland");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Tencent Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2025 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info2.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/etc/os-release", "Host/TencentOS/rpm-list", "Host/cpu");

  exit(0);
}


include('rpm2.inc');

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) || 'TencentOS' >!< os_product) audit(AUDIT_OS_NOT, 'TencentOS');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'TencentOS');
if (! preg(pattern:"^4([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'TencentOS 4.x', 'TencentOS ' + os_version);

if (!get_kb_item('Host/TencentOS/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 && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'TencentOS', cpu);

var constraints = [
  {
    'release': '4',
    'pkgs': [
      {'reference':'xorg-x11-server-Xwayland-23.1.2-6.tl4', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'xorg-x11-server-Xwayland-23.1.2-6.tl4', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'xorg-x11-server-Xwayland-debuginfo-23.1.2-6.tl4', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'xorg-x11-server-Xwayland-debuginfo-23.1.2-6.tl4', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'xorg-x11-server-Xwayland-debugsource-23.1.2-6.tl4', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'xorg-x11-server-Xwayland-debugsource-23.1.2-6.tl4', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'xorg-x11-server-Xwayland-devel-23.1.2-6.tl4', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'xorg-x11-server-Xwayland-devel-23.1.2-6.tl4', 'cpu':'x86_64', '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, 'xorg-x11-server-Xwayland / xorg-x11-server-Xwayland-debuginfo / xorg-x11-server-Xwayland-debugsource / etc');
}