AlmaLinux 9.6 [TuxCare] Security Update: cups-filters / cups-filters-devel / cups-filters-libs Multiple Vulnerabilities (ALMALINUX9.6:CLSA-2026:1772638779)

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

include('compat.inc');

if (description)
{
  script_id(361149);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/01");

  script_cve_id("CVE-2025-57812", "CVE-2025-64503");
  script_xref(name:"CLSA", value:"2026:1772638779");

  script_name(english:"AlmaLinux 9.6 [TuxCare] Security Update: cups-filters / cups-filters-devel / cups-filters-libs Multiple Vulnerabilities (ALMALINUX9.6:CLSA-2026:1772638779)");

  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 multiple vulnerabilities as referenced in the TuxCare
ALMALINUX9.6:CLSA-2026:1772638779 advisory.

  - CUPS is a standards-based, open-source printing system, and `libcupsfilters` contains the code of the
    filters of the former `cups-filters` package as library functions to be used for the data format
    conversion tasks needed in Printer Applications. In CUPS-Filters versions up to and including 1.28.17 and
    libscupsfilters versions 2.0.0 through 2.1.1, CUPS-Filters's `imagetoraster` filter has an out of bounds
    read/write vulnerability in the processing of TIFF image files. While the pixel buffer is allocated with
    the number of pixels times a pre-calculated bytes-per-pixel value, the function which processes these
    pixels is called with a size of the number of pixels times 3. When suitable inputs are passed, the bytes-
    per-pixel value can be set to 1 and bytes outside of the buffer bounds get processed. In order to trigger
    the bug, an attacker must issue a print job with a crafted TIFF file, and pass appropriate print job
    options to control the bytes-per-pixel value of the output format. They must choose a printer
    configuration under which the `imagetoraster` filter or its C-function equivalent
    `cfFilterImageToRaster()` gets invoked. The vulnerability exists in both CUPS-Filters 1.x and the
    successor library libcupsfilters (CUPS-Filters 2.x). In CUPS-Filters 2.x, the vulnerable function is
    `_cfImageReadTIFF() in libcupsfilters`. When this function is invoked as part of
    `cfFilterImageToRaster()`, the caller passes a look-up-table during whose processing the out of bounds
    memory access happens. In CUPS-Filters 1.x, the equivalent functions are all found in the cups-filters
    repository, which is not split into subprojects yet, and the vulnerable code is in `_cupsImageReadTIFF()`,
    which is called through `cupsImageOpen()` from the `imagetoraster` tool. A patch is available in commit
    b69dfacec7f176281782e2f7ac44f04bf9633cfa. (CVE-2025-57812)

  - cups-filters contains backends, filters, and other software required to get the cups printing service
    working on operating systems other than macos. In cups-filters prior to 1.28.18, by crafting a PDF file
    with a large `MediaBox` value, an attacker can cause CUPS-Filter 1.x's `pdftoraster` tool to write beyond
    the bounds of an array. First, a PDF with a large `MediaBox` width value causes `header.cupsWidth` to
    become large. Next, the calculation of `bytesPerLine = (header.cupsBitsPerPixel * header.cupsWidth + 7) /
    8` overflows, resulting in a small value. Then, `lineBuf` is allocated with the small `bytesPerLine` size.
    Finally, `convertLineChunked` calls `writePixel8`, which attempts to write to `lineBuf` outside of its
    buffer size (out of bounds write). In libcupsfilters, the maintainers found the same `bytesPerLine`
    multiplication without overflow check, but the provided test case does not cause an overflow there,
    because the values are different. Commit 50d94ca0f2fa6177613c97c59791bde568631865 contains a patch, which
    is incorporated into cups-filters version 1.28.18. (CVE-2025-64503)

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/tuxcare9.6esu/advisories/2026/clsa-2026_1772638779.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?7a50b500");
  script_set_attribute(attribute:"see_also", value:"https://cve.tuxcare.com/els/releases/CLSA-2026:1772638779");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages based on the guidance in TuxCare advisory ALMALINUX9.6:CLSA-2026:1772638779.");
  script_set_cvss_base_vector("CVSS2#AV:A/AC:H/Au:S/C:P/I:P/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:A/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2025-57812");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"vendor_severity", value:"Low");

  script_set_attribute(attribute:"vuln_publication_date", value:"2025/11/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/03/04");
  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:"^9.6([^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 (cpu !~ "^i[3-6]86$" && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'AlmaLinux', cpu);


var constraints = [
  {
    'release': '9',
    'sp': '6',
    'pkgs': [
      {'reference':'cups-filters-1.28.7-20.el9.tuxcare.els3', 'sp':'6', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'cups-filters-devel-1.28.7-20.el9.tuxcare.els3', 'sp':'6', 'cpu':'i686', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'cups-filters-devel-1.28.7-20.el9.tuxcare.els3', 'sp':'6', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'cups-filters-libs-1.28.7-20.el9.tuxcare.els3', 'sp':'6', 'cpu':'i686', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'cups-filters-libs-1.28.7-20.el9.tuxcare.els3', 'sp':'6', '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_NOTE,
      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, 'cups-filters / cups-filters-devel / cups-filters-libs');
}