Amazon Linux 2 : squid (ALASSQUID4-2023-007)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux 2 Security Advisory ALASSQUID4-2023-007.
##

include('compat.inc');

if (description)
{
  script_id(182047);
  script_version("1.0");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/09/27");

  script_cve_id(
    "CVE-2019-12523",
    "CVE-2019-12525",
    "CVE-2019-12526",
    "CVE-2019-18676",
    "CVE-2019-18678"
  );

  script_name(english:"Amazon Linux 2 : squid (ALASSQUID4-2023-007)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Amazon Linux 2 host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The version of squid installed on the remote host is prior to 4.10-3. It is, therefore, affected by multiple
vulnerabilities as referenced in the ALAS2SQUID4-2023-007 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 3.3.9 through 3.5.28 and 4.x through 4.7. When Squid is configured to use
    Digest authentication, it parses the header Proxy-Authorization. It searches for certain tokens such as
    domain, uri, and qop. Squid checks if this token's value starts with a quote and ends with one. If so, it
    performs a memcpy of its length minus 2. Squid never checks whether the value is just a single quote
    (which would satisfy its requirements), leading to a memcpy of its length minus 1. (CVE-2019-12525)

  - An issue was discovered in Squid before 4.9. URN response handling in Squid suffers from a heap-based
    buffer overflow. When receiving data from a remote server in response to an URN request, Squid fails to
    ensure that the response can fit within the buffer. This leads to attacker controlled data overflowing in
    the heap. (CVE-2019-12526)

  - An issue was discovered in Squid 3.x and 4.x through 4.8. Due to incorrect input validation, there is a
    heap-based buffer overflow that can result in Denial of Service to all clients using the proxy. Severity
    is high due to this vulnerability occurring before normal security checks; any remote client that can
    reach the proxy port can trivially perform the attack via a crafted URI scheme. (CVE-2019-18676)

  - An issue was discovered in Squid 3.x and 4.x through 4.8. It allows attackers to smuggle HTTP requests
    through frontend software to a Squid instance that splits the HTTP Request pipeline differently. The
    resulting Response messages corrupt caches (between a client and Squid) with attacker-controlled content
    at arbitrary URLs. Effects are isolated to software between the attacker client and Squid. There are no
    effects on Squid itself, nor on any upstream servers. The issue is related to a request header containing
    whitespace between a header name and a colon. (CVE-2019-18678)

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://alas.aws.amazon.com/AL2/ALASSQUID4-2023-007.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2019-12523.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2019-12525.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2019-12526.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2019-18676.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2019-18678.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/faqs.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update squid' to update your system.");
  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-2019-12526");

  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:"2019/07/11");
  script_set_attribute(attribute:"patch_publication_date", value:"2023/08/21");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/09/27");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:squid");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:squid-debuginfo");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux:2");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2023 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}

include("rpm.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);

var alas_release = get_kb_item("Host/AmazonLinux/release");
if (isnull(alas_release) || !strlen(alas_release)) audit(AUDIT_OS_NOT, "Amazon Linux");
var os_ver = pregmatch(pattern: "^AL(A|\d+|-\d+)", string:alas_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Amazon Linux");
os_ver = os_ver[1];
if (os_ver != "2")
{
  if (os_ver == 'A') os_ver = 'AMI';
  audit(AUDIT_OS_NOT, "Amazon Linux 2", "Amazon Linux " + os_ver);
}

if (!get_kb_item("Host/AmazonLinux/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

var pkgs = [
    {'reference':'squid-4.10-3.amzn2.0.1', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'squid4'},
    {'reference':'squid-4.10-3.amzn2.0.1', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'squid4'},
    {'reference':'squid-debuginfo-4.10-3.amzn2.0.1', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'squid4'},
    {'reference':'squid-debuginfo-4.10-3.amzn2.0.1', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'squid4'}
];

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 = 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 && (!exists_check || rpm_exists(release:_release, rpm:exists_check))) {
    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 / squid-debuginfo");
}