Oracle Linux 7 : squid (ELSA-2022-22254)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Oracle Linux Security Advisory ELSA-2022-22254.
##

include('compat.inc');

if (description)
{
  script_id(165612);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/10/01");

  script_cve_id("CVE-2019-12520", "CVE-2019-12523", "CVE-2019-12524");

  script_name(english:"Oracle Linux 7 : squid (ELSA-2022-22254)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Oracle Linux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Oracle Linux 7 host has a package installed that is affected by multiple vulnerabilities as referenced in the
ELSA-2022-22254 advisory.

  - An issue was discovered in Squid before 4.9. When handling a URN request, a corresponding HTTP request is
    made. This HTTP request doesn't go through the access checks that incoming HTTP requests go through. This
    causes all access checks to be bypassed and allows access to restricted HTTP servers, e.g., an attacker
    can connect to HTTP servers that only listen on localhost. (CVE-2019-12523)

  - An issue was discovered in Squid through 4.7. When handling requests from users, Squid checks its rules to
    see if the request should be denied. Squid by default comes with rules to block access to the Cache
    Manager, which serves detailed server information meant for the maintainer. This rule is implemented via
    url_regex. The handler for url_regex rules URL decodes an incoming request. This allows an attacker to
    encode their URL to bypass the url_regex check, and gain access to the blocked resource. (CVE-2019-12524)

  - An issue was discovered in Squid through 4.7 and 5. When receiving a request, Squid checks its cache to
    see if it can serve up a response. It does this by making a MD5 hash of the absolute URL of the request.
    If found, it servers the request. The absolute URL can include the decoded UserInfo (username and
    password) for certain protocols. This decoded info is prepended to the domain. This allows an attacker to
    provide a username that has special characters to delimit the domain, and treat the rest of the URL as a
    path or query string. An attacker could first make a request to their domain using an encoded username,
    then when a request for the target domain comes in that decodes to the exact URL, it will serve the
    attacker's HTML instead of the real HTML. On Squid servers that also act as reverse proxies, this allows
    an attacker to gain access to features that only reverse proxies can use, such as ESI. (CVE-2019-12520)

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://linux.oracle.com/errata/ELSA-2022-22254.html");
  script_set_attribute(attribute:"solution", value:
"Update the affected squid package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  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:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2019-12524");

  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:"2019/11/25");
  script_set_attribute(attribute:"patch_publication_date", value:"2022/09/30");
  script_set_attribute(attribute:"plugin_publication_date", value:"2022/10/01");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:oracle:linux:7");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:squid");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2022 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}


include('rpm.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item('Host/OracleLinux')) audit(AUDIT_OS_NOT, 'Oracle Linux');
var release = get_kb_item("Host/RedHat/release");
if (isnull(release) || !pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux)", string:release)) audit(AUDIT_OS_NOT, 'Oracle Linux');
var os_ver = pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux) .*release ([0-9]+(\.[0-9]+)?)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Oracle Linux');
var os_ver = os_ver[1];
if (! preg(pattern:"^7([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Oracle Linux 7', 'Oracle Linux ' + 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$" && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Oracle Linux', cpu);
if ('aarch64' >!< cpu) audit(AUDIT_ARCH_NOT, 'aarch64', cpu);

var pkgs = [
    {'reference':'squid-4.11-3.0.1.el7', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'epoch':'7'}
];

var flag = 0;
foreach var package_array ( pkgs ) {
  var reference = NULL;
  var release = NULL;
  var sp = NULL;
  var cpu = NULL;
  var el_string = NULL;
  var rpm_spec_vers_cmp = NULL;
  var epoch = NULL;
  var allowmaj = NULL;
  var exists_check = NULL;
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (!empty_or_null(package_array['release'])) release = 'EL' + package_array['release'];
  if (!empty_or_null(package_array['sp'])) sp = package_array['sp'];
  if (!empty_or_null(package_array['cpu'])) cpu = package_array['cpu'];
  if (!empty_or_null(package_array['el_string'])) el_string = package_array['el_string'];
  if (!empty_or_null(package_array['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = package_array['rpm_spec_vers_cmp'];
  if (!empty_or_null(package_array['epoch'])) epoch = package_array['epoch'];
  if (!empty_or_null(package_array['allowmaj'])) allowmaj = package_array['allowmaj'];
  if (!empty_or_null(package_array['exists_check'])) exists_check = package_array['exists_check'];
  if (reference && release) {
    if (exists_check) {
        if (rpm_exists(release:release, rpm:exists_check) && rpm_check(release:release, sp:sp, cpu:cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj)) flag++;
    } else {
        if (rpm_check(release:release, sp:sp, cpu:cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj)) flag++;
    }
  }
}

if (flag)
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_HOLE,
      extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'squid');
}