Ubuntu 16.04 ESM / 18.04 ESM / 20.04 ESM : Tor vulnerabilities (USN-5036-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-5036-1. The text
# itself is copyright (C) Canonical, Inc. See
# <https://ubuntu.com/security/notices>. Ubuntu(R) is a registered
# trademark of Canonical, Inc.
##

include('compat.inc');

if (description)
{
  script_id(183153);
  script_version("1.0");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/16");

  script_cve_id(
    "CVE-2019-8955",
    "CVE-2021-28089",
    "CVE-2021-28090",
    "CVE-2021-34548",
    "CVE-2021-34549",
    "CVE-2021-34550",
    "CVE-2021-38385"
  );
  script_xref(name:"USN", value:"5036-1");

  script_name(english:"Ubuntu 16.04 ESM / 18.04 ESM / 20.04 ESM : Tor vulnerabilities (USN-5036-1)");

  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 16.04 ESM / 18.04 ESM / 20.04 ESM host has packages installed that are affected by multiple
vulnerabilities as referenced in the USN-5036-1 advisory.

  - In Tor before 0.3.3.12, 0.3.4.x before 0.3.4.11, 0.3.5.x before 0.3.5.8, and 0.4.x before 0.4.0.2-alpha,
    remote denial of service against Tor clients and relays can occur via memory exhaustion in the KIST cell
    scheduler. (CVE-2019-8955)

  - Tor before 0.4.5.7 allows a remote participant in the Tor directory protocol to exhaust CPU resources on a
    target, aka TROVE-2021-001. (CVE-2021-28089)

  - Tor before 0.4.5.7 allows a remote attacker to cause Tor directory authorities to exit with an assertion
    failure, aka TROVE-2021-002. (CVE-2021-28090)

  - An issue was discovered in Tor before 0.4.6.5, aka TROVE-2021-003. An attacker can forge RELAY_END or
    RELAY_RESOLVED to bypass the intended access control for ending a stream. (CVE-2021-34548)

  - An issue was discovered in Tor before 0.4.6.5, aka TROVE-2021-005. Hashing is mishandled for certain
    retrieval of circuit data. Consequently. an attacker can trigger the use of an attacker-chosen circuit ID
    to cause algorithm inefficiency. (CVE-2021-34549)

  - An issue was discovered in Tor before 0.4.6.5, aka TROVE-2021-006. The v3 onion service descriptor parsing
    allows out-of-bounds memory access, and a client crash, via a crafted onion service descriptor
    (CVE-2021-34550)

  - Tor before 0.3.5.16, 0.4.5.10, and 0.4.6.7 mishandles the relationship between batch-signature
    verification and single-signature verification, leading to a remote assertion failure, aka TROVE-2021-007.
    (CVE-2021-38385)

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://ubuntu.com/security/notices/USN-5036-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected tor and / or tor-geoipdb packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
  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:N/UI:N/S:U/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-38385");

  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:"2019/02/21");
  script_set_attribute(attribute:"patch_publication_date", value:"2022/10/04");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/10/16");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-:esm");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:esm");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:20.04:-:esm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:tor");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:tor-geoipdb");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"Ubuntu Security Notice (C) 2023 Canonical, Inc. / NASL script (C) 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 (! ('16.04' >< os_release || '18.04' >< os_release || '20.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 16.04 / 18.04 / 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': '16.04', 'pkgname': 'tor', 'pkgver': '0.2.9.14-1ubuntu1~16.04.3+esm1'},
    {'osver': '16.04', 'pkgname': 'tor-geoipdb', 'pkgver': '0.2.9.14-1ubuntu1~16.04.3+esm1'},
    {'osver': '18.04', 'pkgname': 'tor', 'pkgver': '0.3.2.10-1ubuntu0.2~esm2'},
    {'osver': '18.04', 'pkgname': 'tor-geoipdb', 'pkgver': '0.3.2.10-1ubuntu0.2~esm2'},
    {'osver': '20.04', 'pkgname': 'tor', 'pkgver': '0.4.2.7-1ubuntu0.1~esm1'},
    {'osver': '20.04', 'pkgname': 'tor-geoipdb', 'pkgver': '0.4.2.7-1ubuntu0.1~esm1'}
];

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, 'tor / tor-geoipdb');
}