AlmaLinux 9.2 [TuxCare] Security Update: frr / frr-selinux Multiple Vulnerabilities (ALMALINUX9.2:CLSA-2026:1778238289)

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

include('compat.inc');

if (description)
{
  script_id(351852);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/30");

  script_cve_id(
    "CVE-2022-40318",
    "CVE-2022-43681",
    "CVE-2023-31489",
    "CVE-2023-46752"
  );
  script_xref(name:"CLSA", value:"2026:1778238289");

  script_name(english:"AlmaLinux 9.2 [TuxCare] Security Update: frr / frr-selinux Multiple Vulnerabilities (ALMALINUX9.2:CLSA-2026:1778238289)");

  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-2026:1778238289 advisory.

  - An issue was discovered in bgpd in FRRouting (FRR) through 8.4. By crafting a BGP OPEN message with an
    option of type 0xff (Extended Length from RFC 9072), attackers may cause a denial of service (assertion
    failure and daemon restart, or out-of-bounds read). This is possible because of inconsistent boundary
    checks that do not account for reading 3 bytes (instead of 2) in this 0xff case. NOTE: this behavior
    occurs in bgp_open_option_parse in the bgp_open.c file, a different location (with a different attack
    vector) relative to CVE-2022-40302. (CVE-2022-40318)

  - An out-of-bounds read exists in the BGP daemon of FRRouting FRR through 8.4. When sending a malformed BGP
    OPEN message that ends with the option length octet (or the option length word, in case of an extended
    OPEN message), the FRR code reads of out of the bounds of the packet, throwing a SIGABRT signal and
    exiting. This results in a bgpd daemon restart, causing a Denial-of-Service condition. (CVE-2022-43681)

  - An issue found in Frrouting bgpd v.8.4.2 allows a remote attacker to cause a denial of service via the
    bgp_capability_llgr() function. (CVE-2023-31489)

  - An issue was discovered in FRRouting FRR through 9.0.1. It mishandles malformed MP_REACH_NLRI data,
    leading to a crash. (CVE-2023-46752)

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_1778238289.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?495303c5");
  script_set_attribute(attribute:"see_also", value:"https://cve.tuxcare.com/els/releases/CLSA-2026:1778238289");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages based on the guidance in TuxCare advisory ALMALINUX9.2:CLSA-2026:1778238289.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:N/I:N/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/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-2022-43681");

  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:"Moderate");

  script_set_attribute(attribute:"vuln_publication_date", value:"2023/05/03");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/05/08");
  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':'frr-8.3.1-5.el9_2.2.alma.tuxcare.els4', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'frr-selinux-8.3.1-5.el9_2.2.alma.tuxcare.els4', 'sp':'2', '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, 'frr / frr-selinux');
}