RHEL 7 : etcd (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 etcd. The text
# itself is copyright (C) Red Hat, Inc.
##

include('compat.inc');

if (description)
{
  script_id(196026);
  script_version("1.0");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/05/11");

  script_cve_id(
    "CVE-2018-1098",
    "CVE-2018-1099",
    "CVE-2020-15113",
    "CVE-2020-15114",
    "CVE-2020-15115",
    "CVE-2020-15136",
    "CVE-2021-28235",
    "CVE-2022-34038",
    "CVE-2023-32082"
  );

  script_name(english:"RHEL 7 : etcd (Unpatched Vulnerability)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Red Hat 7 host is affected by multiple vulnerabilities that will not be patched.");
  script_set_attribute(attribute:"description", value:
"The remote Redhat Enterprise Linux 7 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.

  - etcd: Cross-site request forgery via crafted local POST forms (CVE-2018-1098)

  - etcd: Information discosure via debug function (CVE-2021-28235)

  - DNS rebinding vulnerability found in etcd 3.3.1 and earlier. An attacker can control his DNS records to
    direct to localhost, and trick the browser into sending requests to localhost (or any other address).
    (CVE-2018-1099)

  - In etcd before versions 3.3.23 and 3.4.10, certain directory paths are created (etcd data directory and
    the directory path when provided to automatically generate self-signed certificates for TLS connections
    with clients) with restricted access permissions (700) by using the os.MkdirAll. This function does not
    perform any permission checks when a given directory path exists already. A possible workaround is to
    ensure the directories have the desired permission (700). (CVE-2020-15113)

  - In etcd before versions 3.3.23 and 3.4.10, the etcd gateway is a simple TCP proxy to allow for basic
    service discovery and access. However, it is possible to include the gateway address as an endpoint. This
    results in a denial of service, since the endpoint can become stuck in a loop of requesting itself until
    there are no more available file descriptors to accept connections on the gateway. (CVE-2020-15114)

  - etcd before versions 3.3.23 and 3.4.10 does not perform any password length validation, which allows for
    very short passwords, such as those with a length of one. This may allow an attacker to guess or brute-
    force users' passwords with little computational effort. (CVE-2020-15115)

  - In ectd before versions 3.4.10 and 3.3.23, gateway TLS authentication is only applied to endpoints
    detected in DNS SRV records. When starting a gateway, TLS authentication will only be attempted on
    endpoints identified in DNS SRV records for a given domain, which occurs in the discoverEndpoints
    function. No authentication is performed against endpoints provided in the --endpoints flag. This has been
    fixed in versions 3.4.10 and 3.3.23 with improved documentation and deprecation of the functionality.
    (CVE-2020-15136)

  - Etcd v3.5.4 allows remote attackers to cause a denial of service via function PageWriter.write in
    pagewriter.go. NOTE: the vendor's position is that this is not a vulnerability. (CVE-2022-34038)

  - etcd is a distributed key-value store for the data of a distributed system. Prior to versions 3.4.26 and
    3.5.9, the LeaseTimeToLive API allows access to key names (not value) associated to a lease when `Keys`
    parameter is true, even a user doesn't have read permission to the keys. The impact is limited to a
    cluster which enables auth (RBAC). Versions 3.4.26 and 3.5.9 fix this issue. There are no known
    workarounds. (CVE-2023-32082)

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:P/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:H/I:H/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-2018-1098");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2021-28235");

  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:"2018/04/03");
  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:7");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:etcd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:etcd3");
  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: '7')) audit(AUDIT_OS_NOT, 'Red Hat 7.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':'etcd', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'unpatched_pkg':'etcd'},
      {'reference':'etcd3', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'unpatched_pkg':'etcd3', 'cves':['CVE-2018-1098', 'CVE-2018-1099', 'CVE-2021-28235', 'CVE-2023-32082']}
    ]
  }
];


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, 'etcd / etcd3');
}