AlmaLinux 9.6 [TuxCare] Security Update: openssl / openssl-devel / openssl-libs / openssl-perl Multiple Vulnerabilities (ALMALINUX9.6:CLSA-2026:1788339545)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(361233);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/01");

  script_cve_id("CVE-2026-54874", "CVE-2026-63072");
  script_xref(name:"CLSA", value:"2026:1788339545");

  script_name(english:"AlmaLinux 9.6 [TuxCare] Security Update: openssl / openssl-devel / openssl-libs / openssl-perl Multiple Vulnerabilities (ALMALINUX9.6:CLSA-2026:1788339545)");

  script_set_attribute(attribute:"synopsis", value:
"The AlmaLinux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The AlmaLinux 9.6 host has packages installed that are affected by multiple vulnerabilities as referenced in the TuxCare
ALMALINUX9.6:CLSA-2026:1788339545 advisory.

  - Issue summary: Receiving a DTLS record for a future epoch while a handshake is in progress causes OpenSSL
    to buffer far more memory than the record itself requires. Impact summary: A peer can use a small amount
    of network traffic to make an OpenSSL DTLS endpoint retain a disproportionately large amount of memory,
    which may lead to a Denial of Service. CWE: CWE-405: Asymmetric Resource Consumption (Amplification)
    Description: While a DTLS handshake is in progress, a peer may legitimately have already moved on to the
    next epoch (for example, having sent its ChangeCipherSpec and Finished messages) before the local endpoint
    has processed the same transition, typically because of reordering on the underlying UDP transport.
    OpenSSL buffers such early records so that they can be processed once the local endpoint catches up.
    Buffering a record currently retains the entire read buffer it arrived in, which is sized to hold the
    largest possible DTLS record (around 16 kilobytes), rather than just the bytes that make up the record
    itself. Up to 100 such records may be buffered per connection. As a result, a peer that sends a stream of
    small forged records claiming to belong to the next epoch can cause an OpenSSL DTLS endpoint to retain
    around 1.7 megabytes of memory, despite sending only a small fraction of that amount of data over the
    network. An attacker therefore gains a memory amplification factor of around 1200, and can multiply the
    effect across as many associations as it is able to open, making this a remote memory exhaustion Denial of
    Service risk for DTLS servers. Since the memory retained per connection remains bounded, and any limit an
    application already places on the number of concurrent associations also bounds the total exposure, this
    issue has been assessed as Low severity. FIPS impact: no No FIPS modules are affected by this issue as the
    affected code is outside the OpenSSL FIPS module boundary. OpenSSL 4.0, 3.6, 3.5, 3.4, 3.0, 1.1.1 and
    1.0.2 are vulnerable to this issue. OpenSSL 4.0 users should upgrade to OpenSSL 4.0.2. OpenSSL 3.6 users
    should upgrade to OpenSSL 3.6.4. OpenSSL 3.5 users should upgrade to OpenSSL 3.5.8. OpenSSL 3.4 users
    should upgrade to OpenSSL 3.4.7. OpenSSL 3.0 users should upgrade to OpenSSL 3.0.22. Premium support
    customers only: OpenSSL 1.1.1 users should upgrade to OpenSSL 1.1.1zi OpenSSL 1.0.2 users should upgrade
    to OpenSSL 1.0.2zr This issue was reported on 18 May 2026 by Amazon Web Services. The fix has been
    developed by Matt Caswell. -- cut (non-publishing metadata for internal use) -- Reported by: Amazon Web
    Services Fixed by: Matt Caswell (CVE-2026-54874)

  - Issue summary: OpenSSL CMS decryption sizes the key-unwrap output buffer based on querying the unwrapped
    key size, but the AES-WRAP-PAD unwrap primitive can write and cleanse more bytes than that query reports,
    causing an 8-byte out-of-bounds heap write. Impact summary: An attacker who supplies a crafted CMS message
    can trigger a deterministic 8-byte out-of-bounds heap write when the victim decrypts it with
    CMS_decrypt(), corrupting the heap and typically resulting in a Denial of Service. CWE: CWE-787: Out-of-
    bounds Write Description: The key-wrap OID is potentially attacker-controlled on the wire. CMS unwrapping
    allows both id-aesNNN-wrap-pad and id-aesNNN-wrap ciphers. An attacker can take a legitimate message and
    change a single OID byte to select the padded variant while leaving the message otherwise valid. Since the
    unwrap key is derived from the recipient's private operation (ECDH key agreement or ML-KEM decapsulation),
    the RFC 5649 integrity check cannot pass, and the decryption fails with integrity failure. The write is a
    fixed-size (8-byte), fixed-value (zero) heap overflow immediately past the allocation, requires no special
    configuration, and is reachable from the public CMS_decrypt() function. The consequence is a heap
    corruption leading to a Denial of Service. The fix in the CMS code sizes the unwrap output buffer for the
    worst case so a failed unwrap cannot write past the allocation. FIPS impact: no As the CMS code lives
    outside the FIPS module boundary, no FIPS modules are affected by this CVE. (CVE-2026-63072)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  # https://security.tuxcare.com/csaf/v2/els_os/tuxcare9.6esu/advisories/2026/clsa-2026_1788339545.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?e593875f");
  script_set_attribute(attribute:"see_also", value:"https://cve.tuxcare.com/els/releases/CLSA-2026:1788339545");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages based on the guidance in TuxCare advisory ALMALINUX9.6:CLSA-2026:1788339545.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:P/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-2026-63072");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_set_attribute(attribute:"vendor_severity", value:"Important");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/08/05");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/09/02");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/01");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info2.nasl");
  script_require_keys("Host/OS/extended-third-party", "Host/local_checks_enabled", "Host/AlmaLinux/release", "Host/AlmaLinux/rpm-list", "Host/cpu");

  exit(0);
}
include('rpm2.inc');

var third_party_support = get_kb_item('Host/OS/extended-third-party');
if (empty_or_null(third_party_support) || third_party_support != 'TuxCare') exit(0, 'TuxCare support not enabled.');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_product = get_kb_item('installed_os/local/SSH/0/product');
if (isnull(os_product) || 'AlmaLinux' >!< os_product) audit(AUDIT_OS_NOT, 'AlmaLinux');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'AlmaLinux');
if (! preg(pattern:"^9.6([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'AlmaLinux 9.6', 'AlmaLinux ' + os_version);

if (!get_kb_item('Host/AlmaLinux/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if (cpu !~ "^i[3-6]86$" && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'AlmaLinux', cpu);


var constraints = [
  {
    'release': '9',
    'sp': '6',
    'pkgs': [
      {'reference':'openssl-3.2.2-7.el9_6.tuxcare.1.els10', 'sp':'6', 'cpu':'x86_64', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'openssl-devel-3.2.2-7.el9_6.tuxcare.1.els10', 'sp':'6', 'cpu':'i686', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'openssl-devel-3.2.2-7.el9_6.tuxcare.1.els10', 'sp':'6', 'cpu':'x86_64', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'openssl-libs-3.2.2-7.el9_6.tuxcare.1.els10', 'sp':'6', 'cpu':'i686', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'openssl-libs-3.2.2-7.el9_6.tuxcare.1.els10', 'sp':'6', 'cpu':'x86_64', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
      {'reference':'openssl-perl-3.2.2-7.el9_6.tuxcare.1.els10', 'sp':'6', 'cpu':'x86_64', 'el_string':'el9_6', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'}
    ]
  }
];

var os_release = get_one_kb_item('installed_os/local/SSH/0/release');
var os_sp = get_one_kb_item('Host/*/minor_release');

var flag = 0;
var reference;
var sp;
var _cpu;
var el_string;
var rpm_spec_vers_cmp;
var epoch;
var allowmaj;
var exists_check;
var cves;
foreach var constraint ( constraints ) {
  # Check that the target release is equal to the affected release
  if (!empty_or_null(constraint['release'])){
    if (constraint['release'] != os_release) continue;
  }
  if (!empty_or_null(constraint['sp'])){
    if (constraint['sp'] != os_sp) continue;
  }
  foreach var pkg ( constraint['pkgs'] ) {
    reference = NULL;
    sp = NULL;
    _cpu = NULL;
    el_string = NULL;
    rpm_spec_vers_cmp = NULL;
    epoch = NULL;
    allowmaj = NULL;
    exists_check = NULL;
    cves = NULL;
    if (!empty_or_null(pkg['reference'])) reference = pkg['reference'];
    if (!empty_or_null(pkg['sp'])) sp = pkg['sp'];
    if (!empty_or_null(pkg['cpu'])) _cpu = pkg['cpu'];
    if (!empty_or_null(pkg['el_string'])) el_string = pkg['el_string'];
    if (!empty_or_null(pkg['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = pkg['rpm_spec_vers_cmp'];
    if (!empty_or_null(pkg['epoch'])) epoch = pkg['epoch'];
    if (!empty_or_null(pkg['allowmaj'])) allowmaj = pkg['allowmaj'];
    if (!empty_or_null(pkg['exists_check'])) exists_check = pkg['exists_check'];
    if (!empty_or_null(pkg['cves'])) cves = pkg['cves'];
    if (reference &&
        ## (no known rpm to check OR known rpm_exists)
        (!exists_check || rpm_exists(rpm:exists_check)) &&
        rpm_check(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)
{
  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, 'openssl / openssl-devel / openssl-libs / openssl-perl');
}