Vulnerabilities > CVE-2018-4991 - Improper Certificate Validation vulnerability in Adobe Creative Cloud

047910
CVSS 7.5 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
PARTIAL
network
low complexity
adobe
CWE-295
nessus

Summary

Adobe Creative Cloud Desktop Application versions 4.4.1.298 and earlier have an exploitable Improper certificate validation vulnerability. Successful exploitation could lead to a security bypass.

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Creating a Rogue Certificate Authority Certificate
    An attacker exploits a weakness in the MD5 hash algorithm (weak collision resistance) to generate a certificate signing request (CSR) that contains collision blocks in the "to be signed" part. The attacker specially crafts two different, but valid X.509 certificates that when hashed with the MD5 algorithm would yield the same value. The attacker then sends the CSR for one of the certificates to the Certification Authority which uses the MD5 hashing algorithm. That request is completely valid and the Certificate Authority issues an X.509 certificate to the attacker which is signed with its private key. An attacker then takes that signed blob and inserts it into another X.509 certificate that the attacker generated. Due to the MD5 collision, both certificates, though different, hash to the same value and so the signed blob works just as well in the second certificate. The net effect is that the attackers' second X.509 certificate, which the Certification Authority has never seen, is now signed and validated by that Certification Authority. To make the attack more interesting, the second certificate could be not just a regular certificate, but rather itself a signing certificate. Thus the attacker is able to start their own Certification Authority that is anchored in its root of trust in the legitimate Certification Authority that has signed the attackers' first X.509 certificate. If the original Certificate Authority was accepted by default by browsers, so will now the Certificate Authority set up by the attacker and of course any certificates that it signs. So the attacker is now able to generate any SSL certificates to impersonate any web server, and the user's browser will not issue any warning to the victim. This can be used to compromise HTTPS communications and other types of systems where PKI and X.509 certificates may be used (e.g., VPN, IPSec) .

Nessus

NASL familyWindows
NASL idADOBE_CREATIVE_CLOUD_4_5_0_331.NASL
descriptionThe version of Adobe Creative Cloud Desktop installed on the remote Windows host is prior to 4.5.0.331. It is, therefore, affected by the multiple vulnerabilities as noted in the APSB18-12 advisory. Note that Nessus has not tested for these issues but has instead relied only on the application
last seen2020-06-01
modified2020-06-02
plugin id109729
published2018-05-11
reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/109729
titleAdobe Creative Cloud Desktop < 4.5.0.331 Multiple Vulnerabilities (APSB18-12)
code
#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(109729);
  script_version("1.4");
  script_cvs_date("Date: 2019/11/04");

  script_cve_id("CVE-2018-4873", "CVE-2018-4991", "CVE-2018-4992");
  script_bugtraq_id(104103);

  script_name(english:"Adobe Creative Cloud Desktop < 4.5.0.331 Multiple Vulnerabilities (APSB18-12)");
  script_summary(english:"Checks the version of Creative Cloud.");

  script_set_attribute(attribute:"synopsis", value:
"An application installed on the remote host is affected by multiple
vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The version of Adobe Creative Cloud Desktop installed on the remote
Windows host is prior to 4.5.0.331. It is, therefore, affected by the
multiple vulnerabilities as noted in the APSB18-12 advisory.

Note that Nessus has not tested for these issues but has instead
relied only on the application's self-reported version number.");
  # https://helpx.adobe.com/security/products/creative-cloud/apsb18-12.html
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?a867558d");
  script_set_attribute(attribute:"solution", value:
"Upgrade to Adobe Creative Cloud Desktop version 4.5.0.331 or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  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:H/I:H/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-2018-4991");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/05/08");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/05/08");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/05/11");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:adobe:creative_cloud");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Windows");

  script_copyright(english:"This script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("adobe_creative_cloud_installed.nbin");
  script_require_keys("installed_sw/Adobe Creative Cloud");

  exit(0);
}

include("audit.inc");
include("global_settings.inc");
include("misc_func.inc");
include("install_func.inc");

app = 'Adobe Creative Cloud';

# Pull the installation information from the KB.
install = get_single_install(app_name:app, exit_if_unknown_ver:TRUE);

path = install['path'];
version = install['version'];

# For Adobe products, we compare the highest affected product, rather
# than the "fixed" version, as there is an ambiguous gap between what
# is considered affected and the fix.
highest_affected = "4.4.1.298";
fix = "4.5.0.331";

if (ver_compare(ver:version, fix:highest_affected, strict:FALSE) <= 0)
{
  port = get_kb_item("SMB/transport");
  if (isnull(port))
    port = 445;

  items = make_array("Installed version", version,
                     "Fixed version", fix,
                     "Path", path
                    );

  order = make_list("Path", "Installed version", "Fixed version");
  report = report_items_str(report_items:items, ordered_fields:order);

  security_report_v4(port:port, extra:report, severity:SECURITY_HOLE);
  exit(0);

}
else
  audit(AUDIT_INST_PATH_NOT_VULN, app, version, path);