ISC BIND 9.20.0 < 9.20.11 / 9.20.9-S1 < 9.20.11-S1 / 9.21.0 < 9.21.10 Assertion Failure (cve-2025-40777)

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

include('compat.inc');

if (description)
{
  script_id(298820);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/02/12");

  script_cve_id("CVE-2025-40777");

  script_name(english:"ISC BIND 9.20.0 < 9.20.11 / 9.20.9-S1 < 9.20.11-S1 / 9.21.0 < 9.21.10 Assertion Failure (cve-2025-40777)");

  script_set_attribute(attribute:"synopsis", value:
"The remote name server is affected by an assertion failure vulnerability vulnerability.");
  script_set_attribute(attribute:"description", value:
"The version of ISC BIND installed on the remote host is prior to tested version. It is, therefore, affected by a
vulnerability as referenced in the cve-2025-40777 advisory.

  - If a `named` caching resolver is configured with `serve-stale-enable` `yes`, and with `stale-answer-
    client-timeout` set to `0` (the only allowable value other than `disabled`), and if the resolver, in the
    process of resolving a query, encounters a CNAME chain involving a specific combination of cached or
    authoritative records, the daemon will abort with an assertion failure. This issue affects BIND 9 versions
    9.20.0 through 9.20.10, 9.21.0 through 9.21.9, and 9.20.9-S1 through 9.20.10-S1. (CVE-2025-40777)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://kb.isc.org/v1/docs/cve-2025-40777");
  script_set_attribute(attribute:"solution", value:
"Upgrade to ISC BIND version 9.20.11 / 9.20.11-S1 / 9.21.10 or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/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:L/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-2025-40777");

  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:"2025/07/16");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/07/16");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/02/12");

  script_set_attribute(attribute:"potential_vulnerability", value:"true");
  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:isc:bind");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"DNS");

  script_copyright(english:"This script is Copyright (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("bind_version.nasl");
  script_require_keys("bind/version", "Settings/ParanoidReport");

  exit(0);
}

include('vcf.inc');
include('vcf_extras.inc');

vcf::bind::initialize();

var app_info = vcf::get_app_info(app:'BIND', port:53, kb_ver:'bind/version', service:TRUE, proto:'UDP');

if (report_paranoia < 2) audit(AUDIT_PARANOID);

var constraints = [
  { 'min_version' : '9.20.0', 'max_version' : '9.20.10', 'fixed_version' : '9.20.11' },
  { 'min_version' : '9.20.9-S1', 'max_version' : '9.20.10-S1', 'fixed_version' : '9.20.11-S1' },
  { 'min_version' : '9.21.0', 'max_version' : '9.21.9', 'fixed_version' : '9.21.10' }
];
constraints = vcf::bind::filter_constraints(constraints:constraints, version:app_info.version);

vcf::check_version_and_report(
    app_info:app_info,
    constraints:constraints,
    severity:SECURITY_HOLE
);