RHEL 6 : gnutls (Unpatched Vulnerability)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Red Hat Security Advisory gnutls. The text
# itself is copyright (C) Red Hat, Inc.
##

include('compat.inc');

if (description)
{
  script_id(196513);
  script_version("1.0");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/05/11");

  script_cve_id(
    "CVE-2017-7869",
    "CVE-2018-10844",
    "CVE-2018-10845",
    "CVE-2018-10846",
    "CVE-2018-16868",
    "CVE-2021-4209",
    "CVE-2023-0361",
    "CVE-2023-5981",
    "CVE-2024-0553",
    "CVE-2024-0567",
    "CVE-2024-28834",
    "CVE-2024-28835"
  );

  script_name(english:"RHEL 6 : gnutls (Unpatched Vulnerability)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Red Hat 6 host is affected by multiple vulnerabilities that will not be patched.");
  script_set_attribute(attribute:"description", value:
"The remote Redhat Enterprise Linux 6 host has one or more packages installed that are affected by multiple
vulnerabilities that have been acknowledged by the vendor but will not be patched.

  - gnutls: HMAC-SHA-384 vulnerable to Lucky thirteen attack due to use of wrong constant (CVE-2018-10845)

  - gnutls: incomplete fix for CVE-2023-5981 (CVE-2024-0553)

  - GnuTLS before 2017-02-20 has an out-of-bounds write caused by an integer overflow and heap-based buffer
    overflow related to the cdk_pkt_read function in opencdk/read-packet.c. This issue (which is a subset of
    the vendor's GNUTLS-SA-2017-3 report) is fixed in 3.5.10. (CVE-2017-7869)

  - It was found that the GnuTLS implementation of HMAC-SHA-256 was vulnerable to a Lucky thirteen style
    attack. Remote attackers could use this flaw to conduct distinguishing attacks and plaintext-recovery
    attacks via statistical analysis of timing data using crafted packets. (CVE-2018-10844)

  - A cache-based side channel in GnuTLS implementation that leads to plain text recovery in cross-VM attack
    setting was found. An attacker could use a combination of Just in Time Prime+probe attack in combination
    with Lucky-13 attack to recover plain text using crafted packets. (CVE-2018-10846)

  - A Bleichenbacher type side-channel based padding oracle attack was found in the way gnutls handles
    verification of RSA decrypted PKCS#1 v1.5 data. An attacker who is able to run process on the same
    physical core as the victim process, could use this to extract plaintext or in some cases downgrade any
    TLS connections to a vulnerable server. (CVE-2018-16868)

  - A NULL pointer dereference flaw was found in GnuTLS. As Nettle's hash update functions internally call
    memcpy, providing zero-length input may cause undefined behavior. This flaw leads to a denial of service
    after authentication in rare circumstances. (CVE-2021-4209)

  - A timing side-channel in the handling of RSA ClientKeyExchange messages was discovered in GnuTLS. This
    side-channel can be sufficient to recover the key encrypted in the RSA ciphertext across a network in a
    Bleichenbacher style attack. To achieve a successful decryption the attacker would need to send a large
    amount of specially crafted messages to the vulnerable server. By recovering the secret from the
    ClientKeyExchange message, the attacker would be able to decrypt the application data exchanged over that
    connection. (CVE-2023-0361)

  - A vulnerability was found that the response times to malformed ciphertexts in RSA-PSK ClientKeyExchange
    differ from response times of ciphertexts with correct PKCS#1 v1.5 padding. (CVE-2023-5981)

  - A vulnerability was found in GnuTLS, where a cockpit (which uses gnuTLS) rejects a certificate chain with
    distributed trust. This issue occurs when validating a certificate chain with cockpit-certificate-ensure.
    This flaw allows an unauthenticated, remote client or attacker to initiate a denial of service attack.
    (CVE-2024-0567)

  - A flaw was found in GnuTLS. The Minerva attack is a cryptographic vulnerability that exploits
    deterministic behavior in systems like GnuTLS, leading to side-channel leaks. In specific scenarios, such
    as when using the GNUTLS_PRIVKEY_FLAG_REPRODUCIBLE flag, it can result in a noticeable step in nonce size
    from 513 to 512 bits, exposing a potential timing side-channel. (CVE-2024-28834)

  - A flaw has been discovered in GnuTLS where an application crash can be induced when attempting to verify a
    specially crafted .pem bundle using the certtool --verify-chain command. (CVE-2024-28835)

Note that Nessus has not tested for these issues but has instead relied on the package manager's report that the package
is installed.");
  script_set_attribute(attribute:"solution", value:
"The vendor has acknowledged the vulnerabilities but no solution has been provided. Refer to the vendor for remediation
guidance.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/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:N/UI:N/S:U/C:H/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-2018-10845");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2024-0553");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/03/23");
  script_set_attribute(attribute:"plugin_publication_date", value:"2024/05/11");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:5");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:6");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:8");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:cockpit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gnutls");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:mingw-virt-viewer");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:redhat-virtualization-host");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:rhvm-appliance");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl", "redhat_repos.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list", "Host/cpu");

  exit(0);
}


include('rpm.inc');
include('rhel.inc');

if (!get_kb_item("global_settings/vendor_unpatched"))
exit(0, "Unpatched Vulnerabilities Detection not active.");

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item('Host/RedHat/release');
if (isnull(os_release) || 'Red Hat' >!< os_release) audit(AUDIT_OS_NOT, 'Red Hat');
var os_ver = pregmatch(pattern: "Red Hat Enterprise Linux.*release ([0-9]+(\.[0-9]+)?)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Red Hat');
os_ver = os_ver[1];
if (!rhel_check_release(operator: 'ge', os_version: os_ver, rhel_version: '6')) audit(AUDIT_OS_NOT, 'Red Hat 6.x', 'Red Hat ' + os_ver);

if (!get_kb_item('Host/RedHat/rpm-list')) 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 && 'ppc' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Red Hat', cpu);

var constraints = [
  {
    'pkgs': [
      {'reference':'gnutls', 'release':'6', 'rpm_spec_vers_cmp':TRUE, 'unpatched_pkg':'gnutls'}
    ]
  }
];


var flag = 0;
foreach var constraint_array ( constraints ) {
  var repo_relative_urls = NULL;
  var enterprise_linux_flag = rhel_repo_urls_has_content_dist_rhel(repo_urls:repo_relative_urls);
  foreach var pkg ( constraint_array['pkgs'] ) {
    var unpatched_pkg = NULL;
    var _release = NULL;
    var sp = NULL;
    var el_string = NULL;
    var rpm_spec_vers_cmp = NULL;
    var exists_check = NULL;
    var cves = NULL;
    if (!empty_or_null(pkg['unpatched_pkg'])) unpatched_pkg = pkg['unpatched_pkg'];
    if (!empty_or_null(pkg['release'])) _release = 'RHEL' + pkg['release'];
    if (!empty_or_null(pkg['sp'])) sp = pkg['sp'];
    if (!empty_or_null(pkg['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = pkg['rpm_spec_vers_cmp'];
    if (!empty_or_null(pkg['exists_check'])) exists_check = pkg['exists_check'];
    if (!empty_or_null(pkg['cves'])) cves = pkg['cves'];
    if (unpatched_pkg &&
        _release &&
        (!exists_check || rpm_exists(release:_release, rpm:exists_check)) &&
        unpatched_package_exists(release:_release, package:unpatched_pkg, cves: cves)) flag++;
  }
}

if (flag)
{
  var extra = NULL;
  security_report_v4(
      port       : 0,
      severity   : SECURITY_WARNING,
      extra      : unpatched_packages_report()
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'gnutls');
}