AlmaLinux 9.2 [TuxCare] Security Update: libkcapi / libkcapi-devel / libkcapi-doc / libkcapi-fipscheck / etc Multiple Vulnerabilities (ALMALINUX9.2:CLSA-2026:1786719033)

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

include('compat.inc');

if (description)
{
  script_id(361770);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/01");

  script_cve_id("CVE-2026-71225", "CVE-2026-71226", "CVE-2026-71227");
  script_xref(name:"CLSA", value:"2026:1786719033");

  script_name(english:"AlmaLinux 9.2 [TuxCare] Security Update: libkcapi / libkcapi-devel / libkcapi-doc / libkcapi-fipscheck / etc Multiple Vulnerabilities (ALMALINUX9.2:CLSA-2026:1786719033)");

  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-2026:1786719033 advisory.

  - A flaw was found in libkcapi. When performing one-shot symmetric cipher operations on large inputs (over
    64 KiB) in stateful modes such as Counter (CTR) or Cipher Block Chaining (CBC), the library improperly
    reuses the Initialization Vector (IV) for each internal data chunk. A remote attacker could potentially
    exploit this by making an application that uses libkcapi process specially crafted large inputs. This can
    lead to a significant weakening of data confidentiality, as the repeated IV use can expose relationships
    in encrypted plaintext, and may also affect data integrity by causing incorrect cryptographic processing.
    (CVE-2026-71225)

  - Memory Corruption via Uncanceled AIO Requests on Error: libkcapi's one-shot AIO path can return an error
    before all submitted IOCBs are drained, allowing later kernel writes into caller-owned output buffers.
    (CVE-2026-71226)

  - A flaw was found in libkcapi. A local attacker can influence an application that uses the Asynchronous
    Input/Output (AIO) interface. By reusing an AIO-enabled handle after a prior completion error, the
    _kcapi_aio_read_all() function can enter a non-terminating wait loop. This can lead to a persistent denial
    of service, making the affected application or thread unresponsive. (CVE-2026-71227)

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_1786719033.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?17d4090b");
  script_set_attribute(attribute:"see_also", value:"https://cve.tuxcare.com/els/releases/CLSA-2026:1786719033");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages based on the guidance in TuxCare advisory ALMALINUX9.2:CLSA-2026:1786719033.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:P/I:P/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-71226");

  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:"Important");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/08/05");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/14");
  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':'libkcapi-1.3.1-3.el9.tuxcare.els1', 'sp':'2', 'cpu':'i686', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'libkcapi-1.3.1-3.el9.tuxcare.els1', 'sp':'2', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'libkcapi-devel-1.3.1-3.el9.tuxcare.els1', 'sp':'2', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'libkcapi-doc-1.3.1-3.el9.tuxcare.els1', 'sp':'2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'libkcapi-fipscheck-1.3.1-3.el9.tuxcare.els1', 'sp':'2', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'libkcapi-hmaccalc-1.3.1-3.el9.tuxcare.els1', 'sp':'2', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'libkcapi-static-1.3.1-3.el9.tuxcare.els1', 'sp':'2', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'libkcapi-tests-1.3.1-3.el9.tuxcare.els1', 'sp':'2', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'libkcapi-tools-1.3.1-3.el9.tuxcare.els1', 'sp':'2', '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, 'libkcapi / libkcapi-devel / libkcapi-doc / libkcapi-fipscheck / etc');
}