GLSA-202608-21 : GNU Emacs: Arbitrary code execution

#%NASL_MIN_LEVEL 80900
#
# (C) Tenable, Inc.
#
# @NOAGENT@
#
# The descriptive text and package checks in this plugin were
# extracted from Gentoo Linux Security Advisory GLSA 202608-21.
#
# The advisory text is Copyright (C) 2001-2021 Gentoo Foundation, Inc.
# and licensed under the Creative Commons - Attribution / Share Alike
# license. See http://creativecommons.org/licenses/by-sa/3.0/
#

include('compat.inc');

if (description)
{
  script_id(339063);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/25");

  script_cve_id("CVE-2026-79992");

  script_name(english:"GLSA-202608-21 : GNU Emacs: Arbitrary code execution");

  script_set_attribute(attribute:"synopsis", value:
"");
  script_set_attribute(attribute:"description", value:
"The remote host is affected by the vulnerability described in GLSA-202608-21 (GNU Emacs: Arbitrary code execution)

    A vulnerability has been discovered in GNU Emacs. Please review the CVE identifier referenced below for
    details.

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

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://security.gentoo.org/glsa/202608-21");
  script_set_attribute(attribute:"see_also", value:"https://bugs.gentoo.org/show_bug.cgi?id=981157");
  script_set_attribute(attribute:"solution", value:
"All GNU Emacs 27 users should upgrade to the latest version:

          # emerge --sync
          # emerge --ask --oneshot --verbose >=app-editors/emacs-27.2-r4:27
        
All GNU Emacs 28 users should upgrade to the latest version:

          # emerge --sync
          # emerge --ask --oneshot --verbose >=app-editors/emacs-28.2-r22:28
        
All GNU Emacs 29 users should upgrade to the latest version:

          # emerge --sync
          # emerge --ask --oneshot --verbose >=app-editors/emacs-29.4-r10:29
        
All GNU Emacs 30 users should upgrade to the latest version:

          # emerge --sync
          # emerge --ask --oneshot --verbose >=app-editors/emacs-30.2-r6:30");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/C:C/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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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-2026-79992");

  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:"2026/08/24");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/24");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/24");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:gentoo:linux:emacs");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:gentoo:linux");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Gentoo 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/Gentoo/release", "Host/Gentoo/qpkg-list");

  exit(0);
}
include('qpkg.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item('Host/Gentoo/release')) audit(AUDIT_OS_NOT, 'Gentoo');
if (!get_kb_item('Host/Gentoo/qpkg-list')) audit(AUDIT_PACKAGE_LIST_MISSING);

var flag = 0;

var packages = [
  {
    'name' : 'app-editors/emacs',
    'unaffected' : make_list("ge 27.2-r4", "lt 27.0.0"),
    'vulnerable' : make_list("lt 27.2-r4")
  },
  {
    'name' : 'app-editors/emacs',
    'unaffected' : make_list("ge 28.2-r22", "lt 28.0.0"),
    'vulnerable' : make_list("lt 28.2-r22")
  },
  {
    'name' : 'app-editors/emacs',
    'unaffected' : make_list("ge 29.4-r10", "lt 29.0.0"),
    'vulnerable' : make_list("lt 29.4-r10")
  },
  {
    'name' : 'app-editors/emacs',
    'unaffected' : make_list("ge 30.2-r6", "lt 30.0.0"),
    'vulnerable' : make_list("lt 30.2-r6")
  }
];

foreach var package( packages ) {
  if (isnull(package['unaffected'])) package['unaffected'] = make_list();
  if (isnull(package['vulnerable'])) package['vulnerable'] = make_list();
  if (qpkg_check(package: package['name'] , unaffected: package['unaffected'], vulnerable: package['vulnerable'])) flag++;
}

# This plugin has a different number of unaffected and vulnerable versions for
# one or more packages. To ensure proper detection, a separate line should be 
# used for each fixed/vulnerable version pair.

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : qpkg_report_get()
  );
  exit(0);
}
else
{
  qpkg_tests = list_uniq(qpkg_tests);
  var tested = qpkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'GNU Emacs');
}