Fedora 44 : unbound (2026-e495bd59ef)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##
# The descriptive text and package checks in this plugin were
# extracted from Fedora Security Advisory FEDORA-2026-e495bd59ef
#

include('compat.inc');

if (description)
{
  script_id(330825);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/07/30");

  script_cve_id(
    "CVE-2026-14586",
    "CVE-2026-32665",
    "CVE-2026-40622",
    "CVE-2026-40691",
    "CVE-2026-41292",
    "CVE-2026-41637",
    "CVE-2026-42534",
    "CVE-2026-42955",
    "CVE-2026-44390",
    "CVE-2026-44621",
    "CVE-2026-44687",
    "CVE-2026-44690",
    "CVE-2026-46582",
    "CVE-2026-50045",
    "CVE-2026-50046",
    "CVE-2026-50243",
    "CVE-2026-50248",
    "CVE-2026-50251",
    "CVE-2026-50252",
    "CVE-2026-52863",
    "CVE-2026-54478",
    "CVE-2026-55708",
    "CVE-2026-55717",
    "CVE-2026-55973",
    "CVE-2026-55990",
    "CVE-2026-55991",
    "CVE-2026-56416",
    "CVE-2026-56444"
  );
  script_xref(name:"FEDORA", value:"2026-e495bd59ef");

  script_name(english:"Fedora 44 : unbound (2026-e495bd59ef)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Fedora host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Fedora 44 host has a package installed that is affected by multiple vulnerabilities as referenced in the
FEDORA-2026-e495bd59ef advisory.

    Update to 1.25.2 (rhbz#2506061)

    Security fixes:

    - Fix CVE-2026-14586, Assertion in libngtcp2 when under pressure in high concurrency DNS-over-QUIC
    environments. Thanks to Kunta Chu, Kaihua Wang, and Jianjun Chen from Tsinghua University, for the report.
    - Fix CVE-2026-32665, Remote DNS-over-QUIC denial of service due to `quic-size` budget bypass. Thanks to
    N0zoM1z0 (https://github.com/N0zoM1z0) for the report. In addition, thanks to Kunta Chu, Kaihua Wang, and
    Jianjun Chen from Tsinghua University, for also reporting this issue. In addition, thanks to Qifan Zhang,
    Palo Alto Networks, for also reporting this issue. In addition, thanks to Xuanchao Xie, for also reporting
    this issue.
    - Fix CVE-2026-40691, Packet of death for DNSCrypt over TCP. Thanks to Qifan Zhang, Palo Alto Networks,
    for the report. In addition, thanks to Trung Nguyen (@everping) of CyStack, for also reporting this issue.
    - Fix CVE-2026-41637, Degradation of resolution service from improperly accounted client-terminated DNS-
    over-QUIC queries. Thanks to Qifan Zhang, Palo Alto Networks, for the report.
    - Fix CVE-2026-42955, Extra fix for CVE-2026-40622 to also clamp the TTL of A/AAAA records disallowing a
    one-time 'ghost domain' delegation renewal via glue records. Thanks to Qifan Zhang, Palo Alto Networks,
    for the report.
    - Fix CVE-2026-44621, Libunbound applications configured with 'unwanted-reply-threshold' could eventually
    be abruptly terminated. Thanks to Qifan Zhang, Palo Alto Networks, for the report.
    - Fix CVE-2026-44687, Off-by-one error in 'harden-below-nxdomain' logic can shadow a stub/forward zone by
    a legitimate parent's NXDOMAIN. Thanks to Qifan Zhang, Palo Alto Networks, for the report.
    - Fix CVE-2026-44690, Cross-zone wildcard cache poisoning via RRSIG.labels manipulation. Thanks to Qifan
    Zhang, Palo Alto Networks, for the report.
    - Fix CVE-2026-46582, A wildcard replay, as another piece of data, triggers poisoning in the serve expired
    reply path. Thanks to Qifan Zhang, Palo Alto Networks, for the report.
    - Fix CVE-2026-50045, 'max-global-quota' reset by DNSSEC validation restarts. Thanks to Kunjie Shang,
    University of Science and Technology of China, for the report.
    - Fix CVE-2026-50046, Possible heap use-after-free in an error path when a DoT forwarded query is jostled
    out. Thanks to Qifan Zhang, Palo Alto Networks, for the report.
    - Fix CVE-2026-50243, 'response-ip'/'rpz' can rewrite BOGUS answers instead of returning SERVFAIL. Thanks
    to Qifan Zhang, Palo Alto Networks, for the report.
    - Fix CVE-2026-50248, BOGUS configured primary hostname accepted for XFR in auth/rpz zones. Thanks to
    Qifan Zhang, Palo Alto Networks, for the report.
    - Fix CVE-2026-50251, Attacker supplied `0.0.0.0`/`::` glue triggers defensive full-cache flush. Thanks to
    Qifan Zhang, Palo Alto Networks, for the report.
    - Fix CVE-2026-50252, Possible cache poisoning attack by mapping source port population per thread. Thanks
    to Inbal Schussheim and Amit Klein, Hebrew University, for the report.
    - Fix CVE-2026-52863, Memory corruption could lead to crash and denial of service. Thanks to Qifan Zhang,
    Palo Alto Networks, for the report.
    - Fix CVE-2026-54478, DNS Cookie bypass when combined with proxy-protocol use. Thanks to Qifan Zhang, Palo
    Alto Networks, for the report.
    - Fix CVE-2026-55708, Privacy/configuration issue when adding local data in views through 'unbound-
    control'. Thanks to Qifan Zhang, Palo Alto Networks, for the report.
    - Fix CVE-2026-55717, 'serve-expired-client-timeout' and 'response-ip' CNAME redirect could lead to a
    crash. Thanks to Qifan Zhang, Palo Alto Networks, for the report. In addition, thanks to Xin Wang, Jiapeng
    Li, and Jiajia Liu, Northwestern Polytechnical University, for also reporting this issue.
    - Fix CVE-2026-55973, 'dns-error-reporting: yes' leads to stack buffer overflow. Thanks to Qifan Zhang,
    Palo Alto Networks, for the report.
    - Fix CVE-2026-55990, Packet of death for a DNSCrypt misconfigured Unbound. Thanks to Qifan Zhang, Palo
    Alto Networks, for the report.
    - Fix CVE-2026-55991, Remote DNS-over-QUIC (DoQ) flow-control assertion failure in libngtcp2. Thanks to
    Qifan Zhang, Palo Alto Networks, for the report. In addition, thanks to Xuanchao Xie, for also reporting
    this issue.
    - Fix CVE-2026-56416, Possible heap buffer overflow when validator canonicalizes RDATA that contains
    domain name. Thanks to Qifan Zhang, Palo Alto Networks, for the report.
    - Fix CVE-2026-56444, Degradation of resolution service when 'discard-timeout' and 'serve-expired-client-
    timeout' are combined in unusual configuration. Thanks to Qifan Zhang, Palo Alto Networks, for the report.
    In addition, thanks to Xin Wang, Jiapeng Li, and Jiajia Liu, Northwestern Polytechnical University, for
    also reporting this issue. In addition, thanks to Haruki Oyama (Waseda University), for also reporting
    this issue.

    Source: https://nlnetlabs.nl/projects/unbound/download/#unbound-1-25-2



Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://bodhi.fedoraproject.org/updates/FEDORA-2026-e495bd59ef");
  script_set_attribute(attribute:"solution", value:
"Update the affected unbound package.");
  script_set_cvss_base_vector("CVSS2#AV:A/AC:L/Au:N/C:N/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss4_vector", value:"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:U");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-50252");
  script_set_attribute(attribute:"cvss4_score_source", value:"CVE-2026-41292");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/05/20");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/07/27");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/07/30");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:44");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:unbound");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Fedora 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_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list");

  exit(0);
}


include('rpm2.inc');

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) || 'Fedora' >!< os_product) audit(AUDIT_OS_NOT, 'Fedora');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'Fedora');
if (! preg(pattern:"^44([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'Fedora 44', 'Fedora ' + os_version);

if (!get_kb_item('Host/RedHat/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 && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Fedora', cpu);

var constraints = [
  {
    'release': '44',
    'pkgs': [
      {'reference':'unbound-1.25.2-1.fc44', '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_HOLE,
      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, 'unbound');
}