CentOS Linux 6 [TuxCare] Security Update: kernel / kernel-abi-whitelists / kernel-debug / kernel-debug-devel / etc Multiple Vulnerabilities (CENTOS6:CLSA-2025:1762454401)

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

include('compat.inc');

if (description)
{
  script_id(361913);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/01");

  script_cve_id(
    "CVE-2022-23037",
    "CVE-2022-48757",
    "CVE-2022-49292",
    "CVE-2025-22004",
    "CVE-2025-38477"
  );
  script_xref(name:"CLSA", value:"2025:1762454401");

  script_name(english:"CentOS Linux 6 [TuxCare] Security Update: kernel / kernel-abi-whitelists / kernel-debug / kernel-debug-devel / etc Multiple Vulnerabilities (CENTOS6:CLSA-2025:1762454401)");

  script_set_attribute(attribute:"synopsis", value:
"The CentOS Linux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The CentOS Linux 6 host has packages installed that are affected by multiple vulnerabilities as referenced in the
TuxCare CENTOS6:CLSA-2025:1762454401 advisory.

  - Linux PV device frontends vulnerable to attacks by backends T[his CNA information record relates to
    multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Several Linux PV
    device frontends are using the grant table interfaces for removing access rights of the backends in ways
    being subject to race conditions, resulting in potential data leaks, data corruption by malicious
    backends, and denial of service triggered by malicious backends: blkfront, netfront, scsifront and the
    gntalloc driver are testing whether a grant reference is still in use. If this is not the case, they
    assume that a following removal of the granted access will always succeed, which is not true in case the
    backend has mapped the granted page between those two operations. As a result the backend can keep access
    to the memory page of the guest no matter how the page will be used after the frontend I/O has finished.
    The xenbus driver has a similar problem, as it doesn't check the success of removing the granted access of
    a shared ring buffer. blkfront: CVE-2022-23036 netfront: CVE-2022-23037 scsifront: CVE-2022-23038
    gntalloc: CVE-2022-23039 xenbus: CVE-2022-23040 blkfront, netfront, scsifront, usbfront, dmabuf, xenbus,
    9p, kbdfront, and pvcalls are using a functionality to delay freeing a grant reference until it is no
    longer in use, but the freeing of the related data page is not synchronized with dropping the granted
    access. As a result the backend can keep access to the memory page even after it has been freed and then
    re-used for a different purpose. CVE-2022-23041 netfront will fail a BUG_ON() assertion if it fails to
    revoke access in the rx path. This will result in a Denial of Service (DoS) situation of the guest which
    can be triggered by the backend. CVE-2022-23042 (CVE-2022-23037)

  - In the Linux kernel, the following vulnerability has been resolved: ALSA: oss: Fix PCM OSS buffer
    allocation overflow We've got syzbot reports hitting INT_MAX overflow at vmalloc() allocation that is
    called from snd_pcm_plug_alloc(). Although we apply the restrictions to input parameters, it's based only
    on the hw_params of the underlying PCM device. Since the PCM OSS layer allocates a temporary buffer for
    the data conversion, the size may become unexpectedly large when more channels or higher rates is given;
    in the reported case, it went over INT_MAX, hence it hits WARN_ON(). This patch is an attempt to avoid
    such an overflow and an allocation for too large buffers. First off, it adds the limit of 1MB as the upper
    bound for period bytes. This must be large enough for all use cases, and we really don't want to handle a
    larger temporary buffer than this size. The size check is performed at two places, where the original
    period bytes is calculated and where the plugin buffer size is calculated. In addition, the driver uses
    array_size() and array3_size() for multiplications to catch overflows for the converted period size and
    buffer bytes. (CVE-2022-49292)

  - In the Linux kernel, the following vulnerability has been resolved: net: atm: fix use after free in
    lec_send() The ->send() operation frees skb so save the length before calling ->send() to avoid a use
    after free. (CVE-2025-22004)

  - In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_qfq: Fix race condition
    on qfq_aggregate A race condition can occur when 'agg' is modified in qfq_change_agg (called during
    qfq_enqueue) while other threads access it concurrently. For example, qfq_dump_class may trigger a NULL
    dereference, and qfq_delete_class may cause a use-after-free. This patch addresses the issue by: 1. Moved
    qfq_destroy_class into the critical section. 2. Added sch_tree_lock protection to qfq_dump_class and
    qfq_dump_class_stats. (CVE-2025-38477)

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/centos6els/advisories/2025/clsa-2025_1762454401.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?30093bf9");
  script_set_attribute(attribute:"see_also", value:"https://cve.tuxcare.com/els/releases/CLSA-2025:1762454401");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages based on the guidance in TuxCare advisory CENTOS6:CLSA-2025:1762454401.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:M/Au:N/C:P/I:P/A:P");
  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-2022-23037");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2022-49292");

  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:"2021/07/21");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/11/06");
  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:"CentOS 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/CentOS/release", "Host/CentOS/rpm-list");

  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) || 'CentOS Linux' >!< os_product) audit(AUDIT_OS_NOT, 'CentOS Linux');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'CentOS Linux');
if (! preg(pattern:"^6([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'CentOS Linux 6', 'CentOS Linux ' + os_version);

if (!get_kb_item('Host/CentOS/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, 'CentOS Linux', cpu);


var constraints = [
  {
    'release': '6',
    'pkgs': [
      {'reference':'kernel-2.6.32-754.35.8.el6.tuxcare.els27', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-abi-whitelists-2.6.32-754.35.8.el6.tuxcare.els27', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-debug-2.6.32-754.35.8.el6.tuxcare.els27', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-debug-devel-2.6.32-754.35.8.el6.tuxcare.els27', 'cpu':'i686', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-debug-devel-2.6.32-754.35.8.el6.tuxcare.els27', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-devel-2.6.32-754.35.8.el6.tuxcare.els27', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-firmware-2.6.32-754.35.8.el6.tuxcare.els27', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-headers-2.6.32-754.35.8.el6.tuxcare.els27', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'perf-2.6.32-754.35.8.el6.tuxcare.els27', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'python-perf-2.6.32-754.35.8.el6.tuxcare.els27', '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, 'kernel / kernel-abi-whitelists / kernel-debug / kernel-debug-devel / etc');
}