Amazon Linux 2 : redis (ALASREDIS6-2025-012)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux 2 Security Advisory ALASREDIS6-2025-012.
##

include('compat.inc');

if (description)
{
  script_id(234981);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/04/29");

  script_cve_id("CVE-2025-21605");

  script_name(english:"Amazon Linux 2 : redis (ALASREDIS6-2025-012)");

  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 redis installed on the remote host is prior to 6.2.14-2. It is, therefore, affected by a vulnerability as
referenced in the ALAS2REDIS6-2025-012 advisory.

    Redis is an open source, in-memory database that persists on disk. In versions starting at 2.6 and prior
    to 7.4.3, An unauthenticated client can cause unlimited growth of output buffers, until the server runs
    out of memory or is killed. By default, the Redis configuration does not limit the output buffer of normal
    clients (see client-output-buffer-limit). Therefore, the output buffer can grow unlimitedly over time. As
    a result, the service is exhausted and the memory is unavailable. When password authentication is enabled
    on the Redis server, but no password is provided, the client can still cause the output buffer to grow
    from NOAUTH responses until the system will run out of memory. This issue has been patched in version
    7.4.3. An additional workaround to mitigate this problem without patching the redis-server executable is
    to block access to prevent unauthenticated users from connecting to Redis. This can be done in different
    ways. Either using network access control tools like firewalls, iptables, security groups, etc, or
    enabling TLS and requiring users to authenticate using client side certificates. (CVE-2025-21605)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for this issue 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/ALASREDIS6-2025-012.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2025-21605.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/faqs.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update redis' to update your system.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C");
  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:N/I:N/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-2025-21605");

  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:"2025/04/23");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/04/23");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/04/29");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:redis");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:redis-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:redis-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:redis-doc");
  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) 2025 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 REPOS_FOUND = TRUE;
var extras_list = get_kb_item("Host/AmazonLinux/extras_label_list");
if (isnull(extras_list)) REPOS_FOUND = FALSE;
var repository = '"amzn2extra-redis6"';
if (REPOS_FOUND && (repository >!< extras_list)) exit(0, AFFECTED_REPO_NOT_ENABLED);

var pkgs = [
    {'reference':'redis-6.2.14-2.amzn2.0.2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'redis6'},
    {'reference':'redis-6.2.14-2.amzn2.0.2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'redis6'},
    {'reference':'redis-debuginfo-6.2.14-2.amzn2.0.2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'redis6'},
    {'reference':'redis-debuginfo-6.2.14-2.amzn2.0.2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'redis6'},
    {'reference':'redis-devel-6.2.14-2.amzn2.0.2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'redis6'},
    {'reference':'redis-devel-6.2.14-2.amzn2.0.2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'redis6'},
    {'reference':'redis-doc-6.2.14-2.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'redis6'}
];

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;
  var cves = 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 (!empty_or_null(package_array['cves'])) cves = package_array['cves'];
  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, cves:cves)) flag++;
  }
}

if (flag)
{
  var extra = rpm_report_get();
  if (!REPOS_FOUND) extra = rpm_report_get() + report_repo_caveat();
  security_report_v4(
      port       : 0,
      severity   : SECURITY_HOLE,
      extra      : extra
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "redis / redis-debuginfo / redis-devel / etc");
}