AlmaLinux 9.2 [TuxCare] Security Update: ruby / ruby-default-gems / ruby-devel / ruby-doc / ruby-libs / etc Multiple Vulnerabilities (ALMALINUX9.2:CLSA-2026:1789392152)

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

include('compat.inc');

if (description)
{
  script_id(352872);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/30");

  script_cve_id("CVE-2026-80212", "CVE-2026-80213");
  script_xref(name:"CLSA", value:"2026:1789392152");

  script_name(english:"AlmaLinux 9.2 [TuxCare] Security Update: ruby / ruby-default-gems / ruby-devel / ruby-doc / ruby-libs / etc Multiple Vulnerabilities (ALMALINUX9.2:CLSA-2026:1789392152)");

  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-2026:1789392152 advisory.

  - An issue was discovered in the resolv gem before 0.7.2 for Ruby. Resolv::DNS::Resource.get_class,
    Resolv::DNS::Resource::Generic.create, and Resolv::DNS::SvcParam::Generic.create generate a new class for
    each unknown DNS resource record (type, class) pair, or each unknown SvcParamKey, encountered while
    decoding a response. Each generated class was permanently registered both as a constant on Resource (or
    SvcParam::Generic) and as an entry in a class-lookup hash (ClassHash), and thus the class remained
    reachable through that constant after the response was discarded. Type and class are each 16-bit values,
    and thus an attacker controlling DNS responses (a spoofed response, or a malicious or hijacked upstream
    DNS server) has roughly 2^32 distinct (type, class) pairs to choose from. A single response of a few
    hundred kilobytes carrying tens of thousands of distinct unknown types permanently grows process memory by
    tens of megabytes; repeated responses accumulate without bound and are never reclaimed by garbage
    collection, because the constant keeps each class alive. Any code path that calls
    Resolv::DNS::Message.decode on attacker-influenced DNS responses is affected. resolv is a default gem, and
    thus this is reachable from a plain Ruby installation without any additional dependency. (CVE-2026-80212)

  - An issue was discovered in the resolv gem before 0.7.2 for Ruby. Resolv::DNS::MessageEncoder wrote a DNS
    label's length into a single octet without checking its range. A label longer than 255 octets had its
    length stored modulo 256 but the label data was written unchanged, and thus the bytes on the wire
    described a different name than the one the application asked to encode. RFC 1035 section 2.3.4 limits a
    label to 63 octets, and the two high bits of the length octet are reserved for compression pointers.
    put_string packed the length with put_pack(C, d.length) and put_label used it for labels, and thus any
    value from 0 to 255 could end up as a label length octet, including the reserved 0x40-0xBF range and the
    0xC0-0xFF pointer range. Resolv::DNS::Name.create did not check per-label or total name length either, and
    thus an attacker-controlled hostname reached the encoder unchanged. An application that resolves an
    attacker-controlled hostname sends a query whose wire bytes name a domain the attacker chose. A hostname
    suffix that the application validates against an allowlist becomes padding that never appears on the wire,
    and thus allowlist and egress checks can be bypassed. The recursive resolver caches the response under the
    attacker's name, and DNS logs record that name rather than the one the application asked for. A label
    length whose low octet lands in the 0xC0-0xFF range produces a length octet that conforming parsers read
    as the start of a compression pointer, with the following attacker-controlled byte as the offset.
    (CVE-2026-80213)

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_1789392152.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?d3af06ab");
  script_set_attribute(attribute:"see_also", value:"https://cve.tuxcare.com/els/releases/CLSA-2026:1789392152");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages based on the guidance in TuxCare advisory ALMALINUX9.2:CLSA-2026:1789392152.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:N/I:P/A:N");
  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:C/C:N/I:L/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-80213");

  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:"2026/08/27");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/09/14");
  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 (cpu !~ "^i[3-6]86$" && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'AlmaLinux', cpu);


var constraints = [
  {
    'release': '9',
    'sp': '2',
    'pkgs': [
      {'reference':'ruby-3.0.4-160.el9_2.tuxcare.els19', 'sp':'2', 'cpu':'i686', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'ruby-3.0.4-160.el9_2.tuxcare.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'ruby-default-gems-3.0.4-160.el9_2.tuxcare.els19', 'sp':'2', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'ruby-devel-3.0.4-160.el9_2.tuxcare.els19', 'sp':'2', 'cpu':'i686', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'ruby-devel-3.0.4-160.el9_2.tuxcare.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'ruby-doc-3.0.4-160.el9_2.tuxcare.els19', 'sp':'2', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'ruby-libs-3.0.4-160.el9_2.tuxcare.els19', 'sp':'2', 'cpu':'i686', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'ruby-libs-3.0.4-160.el9_2.tuxcare.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rubygem-bigdecimal-3.0.0-160.el9_2.tuxcare.els19', 'sp':'2', 'cpu':'i686', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rubygem-bigdecimal-3.0.0-160.el9_2.tuxcare.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rubygem-bundler-2.2.33-160.el9_2.tuxcare.els19', 'sp':'2', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rubygem-io-console-0.5.7-160.el9_2.tuxcare.els19', 'sp':'2', 'cpu':'i686', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rubygem-io-console-0.5.7-160.el9_2.tuxcare.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rubygem-irb-1.3.5-160.el9_2.tuxcare.els19', 'sp':'2', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rubygem-json-2.5.1-160.el9_2.tuxcare.els19', 'sp':'2', 'cpu':'i686', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rubygem-json-2.5.1-160.el9_2.tuxcare.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rubygem-minitest-5.14.2-160.el9_2.tuxcare.els19', 'sp':'2', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rubygem-power_assert-1.2.0-160.el9_2.tuxcare.els19', 'sp':'2', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rubygem-psych-3.3.2-160.el9_2.tuxcare.els19', 'sp':'2', 'cpu':'i686', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rubygem-psych-3.3.2-160.el9_2.tuxcare.els19', 'sp':'2', 'cpu':'x86_64', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rubygem-rake-13.0.3-160.el9_2.tuxcare.els19', 'sp':'2', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rubygem-rbs-1.4.0-160.el9_2.tuxcare.els19', 'sp':'2', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rubygem-rdoc-6.3.3-160.el9_2.tuxcare.els19', 'sp':'2', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rubygem-rexml-3.3.3-160.el9_2.tuxcare.els19', 'sp':'2', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rubygem-rss-0.2.9-160.el9_2.tuxcare.els19', 'sp':'2', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rubygem-test-unit-3.3.7-160.el9_2.tuxcare.els19', 'sp':'2', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rubygem-typeprof-0.15.2-160.el9_2.tuxcare.els19', 'sp':'2', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rubygems-3.2.33-160.el9_2.tuxcare.els19', 'sp':'2', 'el_string':'el9_2', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'rubygems-devel-3.2.33-160.el9_2.tuxcare.els19', '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_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, 'ruby / ruby-default-gems / ruby-devel / ruby-doc / ruby-libs / etc');
}