Amazon Linux 2 : amazon-cloudwatch-agent (ALAS-2024-2424)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux 2 Security Advisory ALAS-2024-2424.
##

include('compat.inc');

if (description)
{
  script_id(189333);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/03/08");

  script_cve_id(
    "CVE-2023-39325",
    "CVE-2023-39326",
    "CVE-2023-45142",
    "CVE-2023-47108"
  );
  script_xref(name:"IAVB", value:"2023-B-0080-S");
  script_xref(name:"IAVB", value:"2023-B-0096-S");

  script_name(english:"Amazon Linux 2 : amazon-cloudwatch-agent (ALAS-2024-2424)");

  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 amazon-cloudwatch-agent installed on the remote host is prior to 1.300032.3-1. It is, therefore, affected
by multiple vulnerabilities as referenced in the ALAS2-2024-2424 advisory.

  - A malicious HTTP/2 client which rapidly creates requests and immediately resets them can cause excessive
    server resource consumption. While the total number of requests is bounded by the
    http2.Server.MaxConcurrentStreams setting, resetting an in-progress request allows the attacker to create
    a new request while the existing one is still executing. With the fix applied, HTTP/2 servers now bound
    the number of simultaneously executing handler goroutines to the stream concurrency limit
    (MaxConcurrentStreams). New requests arriving when at the limit (which can only happen after the client
    has reset an existing, in-flight request) will be queued until a handler exits. If the request queue grows
    too large, the server will terminate the connection. This issue is also fixed in golang.org/x/net/http2
    for users manually configuring HTTP/2. The default stream concurrency limit is 250 streams (requests) per
    HTTP/2 connection. This value may be adjusted using the golang.org/x/net/http2 package; see the
    Server.MaxConcurrentStreams setting and the ConfigureServer function. (CVE-2023-39325)

  - A malicious HTTP sender can use chunk extensions to cause a receiver reading from a request or response
    body to read many more bytes from the network than are in the body. A malicious HTTP client can further
    exploit this to cause a server to automatically read a large amount of data (up to about 1GiB) when a
    handler fails to read the entire body of a request. Chunk extensions are a little-used HTTP feature which
    permit including additional metadata in a request or response body sent using the chunked encoding. The
    net/http chunked encoding reader discards this metadata. A sender can exploit this by inserting a large
    metadata segment with each byte transferred. The chunk reader now produces an error if the ratio of real
    body to encoded bytes grows too small. (CVE-2023-39326)

  - OpenTelemetry-Go Contrib is a collection of third-party packages for OpenTelemetry-Go. A handler wrapper
    out of the box adds labels `http.user_agent` and `http.method` that have unbound cardinality. It leads to
    the server's potential memory exhaustion when many malicious requests are sent to it. HTTP header User-
    Agent or HTTP method for requests can be easily set by an attacker to be random and long. The library
    internally uses `httpconv.ServerRequest` that records every value for HTTP `method` and `User-Agent`. In
    order to be affected, a program has to use the `otelhttp.NewHandler` wrapper and not filter any unknown
    HTTP methods or User agents on the level of CDN, LB, previous middleware, etc. Version 0.44.0 fixed this
    issue when the values collected for attribute `http.request.method` were changed to be restricted to a set
    of well-known values and other high cardinality attributes were removed. As a workaround to stop being
    affected, `otelhttp.WithFilter()` can be used, but it requires manual careful configuration to not log
    certain requests entirely. For convenience and safe usage of this library, it should by default mark with
    the label `unknown` non-standard HTTP methods and User agents to show that such requests were made but do
    not increase cardinality. In case someone wants to stay with the current behavior, library API should
    allow to enable it. (CVE-2023-45142)

  - OpenTelemetry-Go Contrib is a collection of third-party packages for OpenTelemetry-Go. Prior to version
    0.46.0, the grpc Unary Server Interceptor out of the box adds labels `net.peer.sock.addr` and
    `net.peer.sock.port` that have unbound cardinality. It leads to the server's potential memory exhaustion
    when many malicious requests are sent. An attacker can easily flood the peer address and port for
    requests. Version 0.46.0 contains a fix for this issue. As a workaround to stop being affected, a view
    removing the attributes can be used. The other possibility is to disable grpc metrics instrumentation by
    passing `otelgrpc.WithMeterProvider` option with `noop.NewMeterProvider`. (CVE-2023-47108)

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/ALAS-2024-2424.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/faqs.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2023-39325.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2023-39326.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2023-45142.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2023-47108.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update amazon-cloudwatch-agent' to update your system.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N");
  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:L/I:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2023-39326");

  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:"2023/10/11");
  script_set_attribute(attribute:"patch_publication_date", value:"2024/01/19");
  script_set_attribute(attribute:"plugin_publication_date", value:"2024/01/23");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:amazon-cloudwatch-agent");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux:2");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Amazon Linux 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");
  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':'amazon-cloudwatch-agent-1.300032.3-1.amzn2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'amazon-cloudwatch-agent-1.300032.3-1.amzn2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE}
];

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_WARNING,
      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, "amazon-cloudwatch-agent");
}