Debian dsa-6453 : libgit2-1.9 - security update

#%NASL_MIN_LEVEL 80900
#
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory dsa-6453. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include('compat.inc');

if (description)
{
  script_id(338355);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/20");

  script_cve_id(
    "CVE-2026-5917",
    "CVE-2026-53583",
    "CVE-2026-53584",
    "CVE-2026-53585",
    "CVE-2026-53586",
    "CVE-2026-53587"
  );

  script_name(english:"Debian dsa-6453 : libgit2-1.9 - security update");

  script_set_attribute(attribute:"synopsis", value:
"The remote Debian host is missing one or more security-related updates.");
  script_set_attribute(attribute:"description", value:
"The remote Debian 13 host has packages installed that are affected by multiple vulnerabilities as referenced in the
dsa-6453 advisory.

    - -------------------------------------------------------------------------
    Debian Security Advisory DSA-6453-1                   [email protected]
    https://www.debian.org/security/                                  Aron Xu
    August 20, 2026                       https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : libgit2
    CVE ID         : CVE-2026-5917 CVE-2026-53583 CVE-2026-53584 CVE-2026-53585
                     CVE-2026-53586 CVE-2026-53587
    Debian Bug     : 1144465

    Multiple security issues were discovered in libgit2, a low-level Git
    library, which could result in the execution of arbitrary commands on a
    remote SSH server, disclosure of credentials, denial of service or the
    creation of directories outside a repository's working tree.

    For the stable distribution (trixie), these problems have been fixed in
    version 1.9.0+ds-2+deb13u1.

    We recommend that you upgrade your libgit2 packages.

    For the detailed security status of libgit2 please refer to
    its security tracker page at:
    https://security-tracker.debian.org/tracker/libgit2

    Further information about Debian Security Advisories, how to apply
    these updates to your system and frequently asked questions can be
    found at: https://www.debian.org/security/

    Mailing list: [email protected]

Tenable has extracted the preceding description block directly from the Debian 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://security-tracker.debian.org/tracker/source-package/libgit2");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-53583");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-53584");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-53585");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-53586");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-53587");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-5917");
  script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/trixie/libgit2");
  script_set_attribute(attribute:"solution", value:
"Upgrade the libgit2-1.9 packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/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:N/AC:L/PR:N/UI:R/S:C/C:H/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:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:U");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-5917");

  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:"2026/07/23");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/20");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/20");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libgit2-1.9");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libgit2-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libgit2-fixtures");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:13.0");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Debian 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/Debian/release", "Host/Debian/dpkg-l");

  exit(0);
}

include('debian_package.inc');

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);

var debian_release = get_kb_item('Host/Debian/release');
if ( isnull(debian_release) ) audit(AUDIT_OS_NOT, 'Debian');
debian_release = chomp(debian_release);
if (! preg(pattern:"^(13)\.[0-9]+", string:debian_release)) audit(AUDIT_OS_NOT, 'Debian 13.0', 'Debian ' + debian_release);
var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Debian', cpu);

var pkgs = [
    {'release': '13.0', 'prefix': 'libgit2-1.9', 'reference': '1.9.0+ds-2+deb13u1'},
    {'release': '13.0', 'prefix': 'libgit2-dev', 'reference': '1.9.0+ds-2+deb13u1'},
    {'release': '13.0', 'prefix': 'libgit2-fixtures', 'reference': '1.9.0+ds-2+deb13u1'}
];

var flag = 0;
foreach package_array ( pkgs ) {
  var _release = NULL;
  var prefix = NULL;
  var reference = NULL;
  if (!empty_or_null(package_array['release'])) _release = package_array['release'];
  if (!empty_or_null(package_array['prefix'])) prefix = package_array['prefix'];
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (_release && prefix && reference) {
    if (deb_check(release:_release, prefix:prefix, reference:reference)) flag++;
  }
}

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : deb_report_get()
  );
  exit(0);
}
else
{
  var tested = deb_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'libgit2-1.9 / libgit2-dev / libgit2-fixtures');
}