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nessusThis script is Copyright (C) 2023 and is owned by Tenable, Inc. or an Affiliate thereof.SUSE_SU-2023-4870-1.NASL
HistoryDec 15, 2023 - 12:00 a.m.

SUSE SLED15 / SLES15 / openSUSE 15 Security Update : cosign (SUSE-SU-2023:4870-1)

2023-12-1500:00:00
This script is Copyright (C) 2023 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
10
suse
sled15
sles15
opensuse
denial of service
vulnerability
cosign
package
oci containers
registry
attacker
cve-2023-46737

CVSS3

5.3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

LOW

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

AI Score

5.6

Confidence

High

EPSS

0.001

Percentile

17.0%

The remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 / openSUSE 15 host has a package installed that is affected by a vulnerability as referenced in the SUSE-SU-2023:4870-1 advisory.

  • Cosign is a sigstore signing tool for OCI containers. Cosign is susceptible to a denial of service by an attacker controlled registry. An attacker who controls a remote registry can return a high number of attestations and/or signatures to Cosign and cause Cosign to enter a long loop resulting in an endless data attack. The root cause is that Cosign loops through all attestations fetched from the remote registry in pkg/cosign.FetchAttestations. The attacker needs to compromise the registry or make a request to a registry they control. When doing so, the attacker must return a high number of attestations in the response to Cosign. The result will be that the attacker can cause Cosign to go into a long or infinite loop that will prevent other users from verifying their data. In Kyvernos case, an attacker whose privileges are limited to making requests to the cluster can make a request with an image reference to their own registry, trigger the infinite loop and deny other users from completing their admission requests. Alternatively, the attacker can obtain control of the registry used by an organization and return a high number of attestations instead the expected number of attestations. The issue can be mitigated rather simply by setting a limit to the limit of attestations that Cosign will loop through. The limit does not need to be high to be within the vast majority of use cases and still prevent the endless data attack. This issue has been patched in version 2.2.1 and users are advised to upgrade.
    (CVE-2023-46737)

Note that Nessus has not tested for this issue but has instead relied only on the application’s self-reported version number.

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The package checks in this plugin were extracted from
# SUSE update advisory SUSE-SU-2023:4870-1. The text itself
# is copyright (C) SUSE.
##

include('compat.inc');

if (description)
{
  script_id(186996);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/12/21");

  script_cve_id("CVE-2023-46737");
  script_xref(name:"SuSE", value:"SUSE-SU-2023:4870-1");

  script_name(english:"SUSE SLED15 / SLES15 / openSUSE 15 Security Update : cosign (SUSE-SU-2023:4870-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote SUSE host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 / openSUSE 15 host has a package installed that is
affected by a vulnerability as referenced in the SUSE-SU-2023:4870-1 advisory.

  - Cosign is a sigstore signing tool for OCI containers. Cosign is susceptible to a denial of service by an
    attacker controlled registry. An attacker who controls a remote registry can return a high number of
    attestations and/or signatures to Cosign and cause Cosign to enter a long loop resulting in an endless
    data attack. The root cause is that Cosign loops through all attestations fetched from the remote registry
    in pkg/cosign.FetchAttestations. The attacker needs to compromise the registry or make a request to a
    registry they control. When doing so, the attacker must return a high number of attestations in the
    response to Cosign. The result will be that the attacker can cause Cosign to go into a long or infinite
    loop that will prevent other users from verifying their data. In Kyvernos case, an attacker whose
    privileges are limited to making requests to the cluster can make a request with an image reference to
    their own registry, trigger the infinite loop and deny other users from completing their admission
    requests. Alternatively, the attacker can obtain control of the registry used by an organization and
    return a high number of attestations instead the expected number of attestations. The issue can be
    mitigated rather simply by setting a limit to the limit of attestations that Cosign will loop through. The
    limit does not need to be high to be within the vast majority of use cases and still prevent the endless
    data attack. This issue has been patched in version 2.2.1 and users are advised to upgrade.
    (CVE-2023-46737)

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://bugzilla.suse.com/1216933");
  # https://lists.suse.com/pipermail/sle-security-updates/2023-December/017420.html
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?629aa757");
  script_set_attribute(attribute:"see_also", value:"https://www.suse.com/security/cve/CVE-2023-46737");
  script_set_attribute(attribute:"solution", value:
"Update the affected cosign package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
  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:N/I:N/A:L");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2023-46737");

  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:"2023/11/07");
  script_set_attribute(attribute:"patch_publication_date", value:"2023/12/14");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/12/15");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:cosign");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:suse_linux:15");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2023 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/cpu", "Host/SuSE/release", "Host/SuSE/rpm-list");

  exit(0);
}


include('rpm.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item("Host/SuSE/release");
if (isnull(os_release) || os_release !~ "^(SLED|SLES|SUSE)") audit(AUDIT_OS_NOT, "SUSE / openSUSE");
var os_ver = pregmatch(pattern: "^(SLE(S|D)(?:_SAP)?\d+|SUSE([\d.]+))", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'SUSE / openSUSE');
os_ver = os_ver[1];
if (! preg(pattern:"^(SLED15|SLED_SAP15|SLES15|SLES_SAP15|SUSE15\.4|SUSE15\.5)$", string:os_ver)) audit(AUDIT_OS_NOT, 'SUSE SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 / openSUSE 15', 'SUSE / openSUSE (' + os_ver + ')');

if (!get_kb_item("Host/SuSE/rpm-list")) 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, 'SUSE / openSUSE (' + os_ver + ')', cpu);

var service_pack = get_kb_item("Host/SuSE/patchlevel");
if (isnull(service_pack)) service_pack = "0";
if (os_ver == "SLED15" && (! preg(pattern:"^(4|5)$", string:service_pack))) audit(AUDIT_OS_NOT, "SLED15 SP4/5", os_ver + " SP" + service_pack);
if (os_ver == "SLED_SAP15" && (! preg(pattern:"^(4|5)$", string:service_pack))) audit(AUDIT_OS_NOT, "SLED_SAP15 SP4/5", os_ver + " SP" + service_pack);
if (os_ver == "SLES15" && (! preg(pattern:"^(4|5)$", string:service_pack))) audit(AUDIT_OS_NOT, "SLES15 SP4/5", os_ver + " SP" + service_pack);
if (os_ver == "SLES_SAP15" && (! preg(pattern:"^(4|5)$", string:service_pack))) audit(AUDIT_OS_NOT, "SLES_SAP15 SP4/5", os_ver + " SP" + service_pack);

var pkgs = [
    {'reference':'cosign-2.2.1-150400.3.14.1', 'sp':'4', 'release':'SLED_SAP15', 'rpm_spec_vers_cmp':TRUE, 'exists_check':['SLES_SAP-release-15.4']},
    {'reference':'cosign-2.2.1-150400.3.14.1', 'sp':'4', 'release':'SLES_SAP15', 'rpm_spec_vers_cmp':TRUE, 'exists_check':['SLES_SAP-release-15.4']},
    {'reference':'cosign-2.2.1-150400.3.14.1', 'sp':'5', 'release':'SLED_SAP15', 'rpm_spec_vers_cmp':TRUE, 'exists_check':['SLES_SAP-release-15.5']},
    {'reference':'cosign-2.2.1-150400.3.14.1', 'sp':'5', 'release':'SLES_SAP15', 'rpm_spec_vers_cmp':TRUE, 'exists_check':['SLES_SAP-release-15.5']},
    {'reference':'cosign-2.2.1-150400.3.14.1', 'sp':'4', 'release':'SLED15', 'rpm_spec_vers_cmp':TRUE, 'exists_check':['SLE_HPC-release-15.4', 'SUSE-Manager-Proxy-release-4.3', 'SUSE-Manager-Server-release-4.3', 'sle-module-basesystem-release-15.4', 'sled-release-15.4', 'sles-release-15.4', 'suse-manager-server-release-4.3']},
    {'reference':'cosign-2.2.1-150400.3.14.1', 'sp':'4', 'release':'SLES15', 'rpm_spec_vers_cmp':TRUE, 'exists_check':['SLE_HPC-release-15.4', 'SUSE-Manager-Proxy-release-4.3', 'SUSE-Manager-Server-release-4.3', 'sle-module-basesystem-release-15.4', 'sled-release-15.4', 'sles-release-15.4', 'suse-manager-server-release-4.3']},
    {'reference':'cosign-2.2.1-150400.3.14.1', 'sp':'5', 'release':'SLED15', 'rpm_spec_vers_cmp':TRUE, 'exists_check':['SLE_HPC-release-15.5', 'sle-module-basesystem-release-15.5', 'sled-release-15.5', 'sles-release-15.5']},
    {'reference':'cosign-2.2.1-150400.3.14.1', 'sp':'5', 'release':'SLES15', 'rpm_spec_vers_cmp':TRUE, 'exists_check':['SLE_HPC-release-15.5', 'sle-module-basesystem-release-15.5', 'sled-release-15.5', 'sles-release-15.5']},
    {'reference':'cosign-2.2.1-150400.3.14.1', 'release':'SUSE15.4', 'rpm_spec_vers_cmp':TRUE, 'exists_check':['openSUSE-release-15.4']},
    {'reference':'cosign-2.2.1-150400.3.14.1', 'release':'SUSE15.5', 'rpm_spec_vers_cmp':TRUE, 'exists_check':['openSUSE-release-15.5']}
];

var ltss_caveat_required = FALSE;
var flag = 0;
foreach var package_array ( pkgs ) {
  var reference = NULL;
  var _release = NULL;
  var sp = NULL;
  var _cpu = NULL;
  var exists_check = NULL;
  var rpm_spec_vers_cmp = 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['exists_check'])) exists_check = package_array['exists_check'];
  if (!empty_or_null(package_array['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = package_array['rpm_spec_vers_cmp'];
  if (reference && _release) {
    if (exists_check) {
      var check_flag = 0;
      foreach var check (exists_check) {
        if (!rpm_exists(release:_release, rpm:check)) continue;
        check_flag++;
      }
      if (!check_flag) continue;
    }
    if (rpm_check(release:_release, sp:sp, cpu:_cpu, reference:reference, rpm_spec_vers_cmp:rpm_spec_vers_cmp)) 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, 'cosign');
}

CVSS3

5.3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

LOW

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

AI Score

5.6

Confidence

High

EPSS

0.001

Percentile

17.0%