AlmaLinux 8 : libevent (ALSA-2026:67908)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The package checks in this plugin were extracted from
# AlmaLinux Security Advisory ALSA-2026:67908.
##

include('compat.inc');

if (description)
{
  script_id(346872);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/17");

  script_cve_id(
    "CVE-2026-63382",
    "CVE-2026-63383",
    "CVE-2026-63384",
    "CVE-2026-63385",
    "CVE-2026-63387",
    "CVE-2026-63388"
  );
  script_xref(name:"ALSA", value:"2026:67908");
  script_xref(name:"RHSA", value:"2026:67908");

  script_name(english:"AlmaLinux 8 : libevent (ALSA-2026:67908)");

  script_set_attribute(attribute:"synopsis", value:
"The remote AlmaLinux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote AlmaLinux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the
ALSA-2026:67908 advisory.

    * libevent: Libevent: Denial of Service via malformed RPC data (CVE-2026-63383)
      * libevent: Libevent: Off-by-one stack buffer overflow leading to denial of service or data corruption
    (CVE-2026-63387)
      * libevent: Libevent: Denial of Service via integer conversion error in `evtag_unmarshal_header`
    (CVE-2026-63384)
      * libevent ev[http:](http:) Multiple HTTP Parser Bugs Enable Request Smuggling (CVE-2026-63382)
      * libevent: Libevent: Arbitrary code execution via heap out-of-bounds write in AF_UNIX handling
    (CVE-2026-63388)
      * libevent: Libevent: HTTP header handling bugs create risk of access control bypass. (CVE-2026-63385)

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

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://errata.almalinux.org/8/ALSA-2026-67908.html");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2026:67908");
  script_set_attribute(attribute:"solution", value:
"Update the affected libevent, libevent-devel and / or libevent-doc packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/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:L/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:"cvss4_vector", value:"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:L/SI:L/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:U");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-63387");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2026-63388");
  script_set_attribute(attribute:"cvss4_score_source", value:"CVE-2026-63385");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(125, 190, 444, 787);

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/08/20");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/09/16");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/17");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:libevent");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:libevent-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:libevent-doc");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8::appstream");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8::baseos");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8::highavailability");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8::nfv");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8::powertools");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8::realtime");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8::resilientstorage");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8::sap");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8::sap_hana");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8::supplementary");
  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_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/AlmaLinux/release", "Host/AlmaLinux/rpm-list", "Host/cpu");

  exit(0);
}


include('rpm2.inc');

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:"^8([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'AlmaLinux 8.x', '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 ('aarch64' >!< cpu && 'ppc' >!< cpu && 's390' >!< cpu && 'x86_64' >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'AlmaLinux', cpu);

var constraints = [
  {
    'release': '8',
    'pkgs': [
      {'reference':'libevent-2.1.8-11.el8_10', 'el_string':'el8_10', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
      {'reference':'libevent-devel-2.1.8-11.el8_10', 'el_string':'el8_10', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'},
      {'reference':'libevent-doc-2.1.8-11.el8_10', 'el_string':'el8_10', 'rpm_spec_vers_cmp':TRUE, 'epoch':'0'}
    ]
  }
];

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, 'libevent / libevent-devel / libevent-doc');
}