Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 25.10 : Rack vulnerabilities (USN-8182-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-8182-1. The text
# itself is copyright (C) Canonical, Inc. See
# <https://ubuntu.com/security/notices>. Ubuntu(R) is a registered
# trademark of Canonical, Inc.
##

include('compat.inc');

if (description)
{
  script_id(307009);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/04/17");

  script_cve_id(
    "CVE-2026-26961",
    "CVE-2026-26962",
    "CVE-2026-32762",
    "CVE-2026-34230",
    "CVE-2026-34763",
    "CVE-2026-34785",
    "CVE-2026-34786",
    "CVE-2026-34826",
    "CVE-2026-34827",
    "CVE-2026-34829",
    "CVE-2026-34830",
    "CVE-2026-34831",
    "CVE-2026-34835"
  );
  script_xref(name:"USN", value:"8182-1");

  script_name(english:"Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 25.10 : Rack vulnerabilities (USN-8182-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 25.10 host has packages
installed that are affected by multiple vulnerabilities as referenced in the USN-8182-1 advisory.

    Andrew Lacambra discovered that Rack did not properly parse certain regular expressions. An attacker could
    possibly use this issue to bypass network security filters. This issue only affected Ubuntu 20.04 LTS,
    Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 25.10. (CVE-2026-26961)

    William T. Nelson discovered that Rack did not handle multipart headers correctly. An attacker could
    possibly use this issue to cause downstream parsing issues or a denial of service. This issue only
    affected Ubuntu 25.10. (CVE-2026-26962)

    It was discovered that Rack did not handle the Forwarded header correctly. An attacker could possibly use
    this issue to manipulate header values. This issue only affected Ubuntu 25.10. (CVE-2026-32762)

    It was discovered that Rack could consume excessive CPU when handling certain Accept-Encoding values. An
    attacker could possibly use this issue to cause a denial of service. (CVE-2026-34230)

    Haruki Oyama discovered that certain configurations of Rack could erroneously fail to derive the displayed
    directory path, and expose the full filesystem path. An attacker could possibly use this issue to disclose
    deployment details such as layout and usernames. (CVE-2026-34763)

    It was discovered that Rack did not properly handle static file paths. An attacker could possibly use this
    issue to exfiltrate unintentionally served data. (CVE-2026-34785)

    Haruki Oyama discovered that Rack did not apply header rules to certain requests for URL-encoded static
    paths. An attacker could possibly use this issue to bypass security-relevant response headers. This issue
    only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 25.10.
    (CVE-2026-34786)

    It was discovered that Rack did not limit the number of ranges requested in the Range header. An attacker
    could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 16.04 LTS,
    Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 25.10. (CVE-2026-34826)

    It was discovered that Rack could consume excessive CPU when parsing certain multipart parameters. An
    attacker could possibly use this to cause a denial of service. This issue only affected Ubuntu 25.10.
    (CVE-2026-34827)

    It was discovered that Rack could consume unbounded disk space when handling requests without a Content-
    Length header. An attacker could possibly use this issue to cause a denial of service. This issue only
    affected Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 25.10. (CVE-2026-34829)

    Mehtab Zafar discovered that Rack directly interpreted the X-Accel-Mapping header as a regular expression
    without escaping. An attacker could possibly use this issue to exfiltrate arbitrary files from internal
    locations. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04
    LTS, Ubuntu 24.04 LTS, and Ubuntu 25.10. (CVE-2026-34830)

    It was discovered that Rack did not properly handle messages with Unicode. An attacker could possibly use
    this issue to cause a denial of service. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and
    Ubuntu 25.10. (CVE-2026-34831)

    It was discovered that Rack did not properly parse the Host header. An attacker could possibly use this
    issue to bypass security filters or poison generated links. This issue only affected Ubuntu 25.10.
    (CVE-2026-34835)

Tenable has extracted the preceding description block directly from the Ubuntu 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://ubuntu.com/security/notices/USN-8182-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:N/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:POC/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:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-34830");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/04/02");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/04/17");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/04/17");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:14.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:20.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:22.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:24.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:25.10");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:librack-ruby");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:librack-ruby1.8");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:librack-ruby1.9.1");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:ruby-rack");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"Ubuntu Security Notice (C) 2026 Canonical, Inc. / NASL script (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl", "ubuntu_pro_sub_detect.nasl");
  script_require_keys("Host/cpu", "Host/Ubuntu", "Host/Ubuntu/release", "Host/Debian/dpkg-l");

  exit(0);
}

include('debian_package.inc');

if ( ! get_kb_item('Host/local_checks_enabled') ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item('Host/Ubuntu/release');
if ( isnull(os_release) ) audit(AUDIT_OS_NOT, 'Ubuntu');
os_release = chomp(os_release);
if (! ('14.04' >< os_release || '16.04' >< os_release || '18.04' >< os_release || '20.04' >< os_release || '22.04' >< os_release || '24.04' >< os_release || '25.10' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 14.04 / 16.04 / 18.04 / 20.04 / 22.04 / 24.04 / 25.10', 'Ubuntu ' + os_release);
if ( ! get_kb_item('Host/Debian/dpkg-l') ) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Ubuntu', cpu);
var ubuntu_pro_detected = get_kb_item('Host/Ubuntu/Pro/Services/esm-apps');
ubuntu_pro_detected = !empty_or_null(ubuntu_pro_detected);

var pro_caveat_needed = FALSE;

var pkgs = [
    {'osver': '14.04', 'pkgname': 'librack-ruby', 'pkgver': '1.5.2-3+deb8u3ubuntu1~esm11', 'ubuntu_pro': TRUE, 'cves': ['CVE-2026-34230', 'CVE-2026-34763', 'CVE-2026-34785']},
    {'osver': '14.04', 'pkgname': 'librack-ruby1.8', 'pkgver': '1.5.2-3+deb8u3ubuntu1~esm11', 'ubuntu_pro': TRUE, 'cves': ['CVE-2026-34230', 'CVE-2026-34763', 'CVE-2026-34785']},
    {'osver': '14.04', 'pkgname': 'librack-ruby1.9.1', 'pkgver': '1.5.2-3+deb8u3ubuntu1~esm11', 'ubuntu_pro': TRUE, 'cves': ['CVE-2026-34230', 'CVE-2026-34763', 'CVE-2026-34785']},
    {'osver': '14.04', 'pkgname': 'ruby-rack', 'pkgver': '1.5.2-3+deb8u3ubuntu1~esm11', 'ubuntu_pro': TRUE, 'cves': ['CVE-2026-34230', 'CVE-2026-34763', 'CVE-2026-34785']},
    {'osver': '16.04', 'pkgname': 'ruby-rack', 'pkgver': '1.6.4-3ubuntu0.2+esm10', 'ubuntu_pro': TRUE, 'cves': ['CVE-2026-34230', 'CVE-2026-34763', 'CVE-2026-34785', 'CVE-2026-34826', 'CVE-2026-34830']},
    {'osver': '18.04', 'pkgname': 'ruby-rack', 'pkgver': '1.6.4-4ubuntu0.2+esm10', 'ubuntu_pro': TRUE, 'cves': ['CVE-2026-34230', 'CVE-2026-34763', 'CVE-2026-34785', 'CVE-2026-34786', 'CVE-2026-34826', 'CVE-2026-34830']},
    {'osver': '20.04', 'pkgname': 'ruby-rack', 'pkgver': '2.0.7-2ubuntu0.1+esm10', 'ubuntu_pro': TRUE, 'cves': ['CVE-2026-26961', 'CVE-2026-34230', 'CVE-2026-34763', 'CVE-2026-34785', 'CVE-2026-34786', 'CVE-2026-34826', 'CVE-2026-34829', 'CVE-2026-34830']},
    {'osver': '22.04', 'pkgname': 'ruby-rack', 'pkgver': '2.1.4-5ubuntu1.2+esm3', 'ubuntu_pro': TRUE, 'cves': ['CVE-2026-26961', 'CVE-2026-34230', 'CVE-2026-34763', 'CVE-2026-34785', 'CVE-2026-34786', 'CVE-2026-34826', 'CVE-2026-34829', 'CVE-2026-34830', 'CVE-2026-34831']},
    {'osver': '24.04', 'pkgname': 'ruby-rack', 'pkgver': '2.2.7-1ubuntu0.7', 'ubuntu_pro': FALSE, 'cves': ['CVE-2026-26961', 'CVE-2026-34230', 'CVE-2026-34763', 'CVE-2026-34785', 'CVE-2026-34786', 'CVE-2026-34826', 'CVE-2026-34829', 'CVE-2026-34830', 'CVE-2026-34831']},
    {'osver': '25.10', 'pkgname': 'ruby-rack', 'pkgver': '3.1.16-0.1ubuntu0.3', 'ubuntu_pro': FALSE, 'cves': ['CVE-2026-26961', 'CVE-2026-26962', 'CVE-2026-32762', 'CVE-2026-34230', 'CVE-2026-34763', 'CVE-2026-34785', 'CVE-2026-34786', 'CVE-2026-34826', 'CVE-2026-34827', 'CVE-2026-34829', 'CVE-2026-34830', 'CVE-2026-34831', 'CVE-2026-34835']}
];

var flag = 0;
foreach var package_array ( pkgs ) {
  var osver = NULL;
  var pkgname = NULL;
  var pkgver = NULL;
  if (!empty_or_null(package_array['osver'])) osver = package_array['osver'];
  if (!empty_or_null(package_array['pkgname'])) pkgname = package_array['pkgname'];
  if (!empty_or_null(package_array['pkgver'])) pkgver = package_array['pkgver'];
  if (!empty_or_null(package_array['cves'])) cves = package_array['cves'];
  var pro_required = NULL;
  if (!empty_or_null(package_array['ubuntu_pro'])) pro_required = package_array['ubuntu_pro'];
  if (osver && pkgname && pkgver) {
    if (deb_check(release:osver, prefix:pkgname, reference:pkgver, cves:cves)) {
        flag++;
        if (!ubuntu_pro_detected && !pro_caveat_needed) pro_caveat_needed = pro_required;
    }
  }
}

if (flag)
{
  var extra = '';
  if (pro_caveat_needed) {
    extra += 'NOTE: This vulnerability check contains fixes that apply to packages only \n';
    extra += 'available in Ubuntu ESM repositories. Access to these package security updates \n';
    extra += 'require an Ubuntu Pro subscription.\n\n';
  }
  extra += ubuntu_report_get();
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : extra
  );
  exit(0);
}
else
{
  var tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'librack-ruby / librack-ruby1.8 / librack-ruby1.9.1 / ruby-rack');
}