AlmaLinux 9.2 [TuxCare] Security Update: mod_http2 (ALMALINUX9.2:CLSA-2026:1778873714)

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

include('compat.inc');

if (description)
{
  script_id(352110);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/30");

  script_cve_id("CVE-2023-45802");
  script_xref(name:"CLSA", value:"2026:1778873714");

  script_name(english:"AlmaLinux 9.2 [TuxCare] Security Update: mod_http2 (ALMALINUX9.2:CLSA-2026:1778873714)");

  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 a package installed that is affected by a vulnerability as referenced in the TuxCare
ALMALINUX9.2:CLSA-2026:1778873714 advisory.

  - When a HTTP/2 stream was reset (RST frame) by a client, there was a time window were the request's memory
    resources were not reclaimed immediately. Instead, de-allocation was deferred to connection close. A
    client could send new requests and resets, keeping the connection busy and open and causing the memory
    footprint to keep on growing. On connection close, all resources were reclaimed, but the process might run
    out of memory before that. This was found by the reporter during testing of CVE-2023-44487 (HTTP/2 Rapid
    Reset Exploit) with their own test client. During normal HTTP/2 use, the probability to hit this bug is
    very low. The kept memory would not become noticeable before the connection closes or times out. Users are
    recommended to upgrade to version 2.4.58, which fixes the issue. (CVE-2023-45802)

Note that Nessus has not tested for this issue 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_1778873714.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?10e9a39d");
  script_set_attribute(attribute:"see_also", value:"https://cve.tuxcare.com/els/releases/CLSA-2026:1778873714");
  script_set_attribute(attribute:"solution", value:
"Update the affected mod_http2 package based on the guidance in TuxCare advisory ALMALINUX9.2:CLSA-2026:1778873714.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:N/I:N/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/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-2023-45802");

  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:"Moderate");

  script_set_attribute(attribute:"vuln_publication_date", value:"2023/10/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/05/15");
  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':'mod_http2-1.15.19-4.el9.4.tuxcare.els3', '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, 'mod_http2');
}