Ubuntu 20.04 LTS : libslirp vulnerabilities (USN-5009-1)

#%NASL_MIN_LEVEL 70300
##
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-5009-1. The text
# itself is copyright (C) Canonical, Inc. See
# <https://ubuntu.com/security/notices>. Ubuntu(R) is a registered
# trademark of Canonical, Inc.
##

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(151679);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/23");

  script_cve_id(
    "CVE-2020-29129",
    "CVE-2020-29130",
    "CVE-2021-3592",
    "CVE-2021-3593",
    "CVE-2021-3594",
    "CVE-2021-3595"
  );
  script_xref(name:"USN", value:"5009-1");

  script_name(english:"Ubuntu 20.04 LTS : libslirp vulnerabilities (USN-5009-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Ubuntu 20.04 LTS / 20.10 / 21.04 host has packages installed that are affected by multiple vulnerabilities as
referenced in the USN-5009-1 advisory.

  - ncsi.c in libslirp through 4.3.1 has a buffer over-read because it tries to read a certain amount of
    header data even if that exceeds the total packet length. (CVE-2020-29129)

  - slirp.c in libslirp through 4.3.1 has a buffer over-read because it tries to read a certain amount of
    header data even if that exceeds the total packet length. (CVE-2020-29130)

  - An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw
    exists in the bootp_input() function and could occur while processing a udp packet that is smaller than
    the size of the 'bootp_t' structure. A malicious guest could use this flaw to leak 10 bytes of
    uninitialized heap memory from the host. The highest threat from this vulnerability is to data
    confidentiality. This flaw affects libslirp versions prior to 4.6.0. (CVE-2021-3592)

  - An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw
    exists in the udp6_input() function and could occur while processing a udp packet that is smaller than the
    size of the 'udphdr' structure. This issue may lead to out-of-bounds read access or indirect host memory
    disclosure to the guest. The highest threat from this vulnerability is to data confidentiality. This flaw
    affects libslirp versions prior to 4.6.0. (CVE-2021-3593)

  - An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw
    exists in the udp_input() function and could occur while processing a udp packet that is smaller than the
    size of the 'udphdr' structure. This issue may lead to out-of-bounds read access or indirect host memory
    disclosure to the guest. The highest threat from this vulnerability is to data confidentiality. This flaw
    affects libslirp versions prior to 4.6.0. (CVE-2021-3594)

  - An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw
    exists in the tftp_input() function and could occur while processing a udp packet that is smaller than the
    size of the 'tftp_t' structure. This issue may lead to out-of-bounds read access or indirect host memory
    disclosure to the guest. The highest threat from this vulnerability is to data confidentiality. This flaw
    affects libslirp versions prior to 4.6.0. (CVE-2021-3595)

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://ubuntu.com/security/notices/USN-5009-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected libslirp-dev and / or libslirp0 packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:P/I:N/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-29130");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/11/26");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/07/15");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/07/16");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:20.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libslirp-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libslirp0");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Ubuntu Local Security Checks");

  script_copyright(english:"Ubuntu Security Notice (C) 2021-2023 Canonical, Inc. / NASL script (C) 2021-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/cpu", "Host/Ubuntu", "Host/Ubuntu/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);
var os_release = get_kb_item('Host/Ubuntu/release');
if ( isnull(os_release) ) audit(AUDIT_OS_NOT, 'Ubuntu');
os_release = chomp(os_release);
if (! ('20.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 20.04', 'Ubuntu ' + os_release);
if ( ! get_kb_item('Host/Debian/dpkg-l') ) 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, 'Ubuntu', cpu);

var pkgs = [
    {'osver': '20.04', 'pkgname': 'libslirp-dev', 'pkgver': '4.1.0-2ubuntu2.2'},
    {'osver': '20.04', 'pkgname': 'libslirp0', 'pkgver': '4.1.0-2ubuntu2.2'}
];

var flag = 0;
foreach package_array ( pkgs ) {
  var osver = NULL;
  var pkgname = NULL;
  var pkgver = NULL;
  if (!empty_or_null(package_array['osver'])) osver = package_array['osver'];
  if (!empty_or_null(package_array['pkgname'])) pkgname = package_array['pkgname'];
  if (!empty_or_null(package_array['pkgver'])) pkgver = package_array['pkgver'];
  if (osver && pkgname && pkgver) {
    if (ubuntu_check(osver:osver, pkgname:pkgname, pkgver:pkgver)) flag++;
  }
}

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : ubuntu_report_get()
  );
  exit(0);
}
else
{
  var tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'libslirp-dev / libslirp0');
}