Vulnerabilities > CVE-2012-5518 - Improper Certificate Validation vulnerability in Ovirt Vdsm

047910
CVSS 4.3 - MEDIUM
Attack vector
NETWORK
Attack complexity
MEDIUM
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
PARTIAL
Availability impact
NONE
network
ovirt
CWE-295
nessus

Summary

vdsm: certificate generation upon node creation allowing vdsm to start and serve requests from anyone who has a matching key (and certificate)

Vulnerable Configurations

Part Description Count
Application
Ovirt
1

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 familyFedora Local Security Checks
NASL idFEDORA_2013-0210.NASL
descriptionMove the certificate generation to the service startup Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
last seen2020-03-17
modified2013-03-13
plugin id65229
published2013-03-13
reporterThis script is Copyright (C) 2013-2020 Tenable Network Security, Inc.
sourcehttps://www.tenable.com/plugins/nessus/65229
titleFedora 17 : vdsm-4.10.0-13.fc17 (2013-0210)
code
#%NASL_MIN_LEVEL 80502
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Fedora Security Advisory 2013-0210.
#

include("compat.inc");

if (description)
{
  script_id(65229);
  script_version("1.7");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/03/12");

  script_cve_id("CVE-2012-5518");
  script_xref(name:"FEDORA", value:"2013-0210");

  script_name(english:"Fedora 17 : vdsm-4.10.0-13.fc17 (2013-0210)");
  script_summary(english:"Checks rpm output for the updated package.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Fedora host is missing a security update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"Move the certificate generation to the service startup

Note that Tenable Network Security has extracted the preceding
description block directly from the Fedora security advisory. Tenable
has attempted to automatically clean and format it as much as possible
without introducing additional issues."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.redhat.com/show_bug.cgi?id=875367"
  );
  # https://lists.fedoraproject.org/pipermail/package-announce/2013-March/099980.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?b9bdd6b2"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected vdsm package.");
  script_set_cvss_base_vector("CVSS2#AV:A/AC:H/Au:N/C:C/I:C/A:C");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:vdsm");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:17");

  script_set_attribute(attribute:"patch_publication_date", value:"2013/01/05");
  script_set_attribute(attribute:"plugin_publication_date", value:"2013/03/13");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2013-2020 Tenable Network Security, Inc.");
  script_family(english:"Fedora Local Security Checks");

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

  exit(0);
}


include("audit.inc");
include("global_settings.inc");
include("rpm.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/RedHat/release");
if (isnull(release) || "Fedora" >!< release) audit(AUDIT_OS_NOT, "Fedora");
os_ver = eregmatch(pattern: "Fedora.*release ([0-9]+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Fedora");
os_ver = os_ver[1];
if (! ereg(pattern:"^17([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 17.x", "Fedora " + os_ver);

if (!get_kb_item("Host/RedHat/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

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

flag = 0;
if (rpm_check(release:"FC17", reference:"vdsm-4.10.0-13.fc17")) flag++;


if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:rpm_report_get());
  else security_warning(0);
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "vdsm");
}