Virtuozzo 7 : readykernel-patch (VZA-2019-045)

2020-02-04T00:00:00
ID VIRTUOZZO_VZA-2019-045.NASL
Type nessus
Reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
Modified 2020-04-02T00:00:00

Description

According to the version of the vzkernel package and the readykernel-patch installed, the Virtuozzo installation on the remote host is affected by the following vulnerabilities :

  • A use-after-free vulnerability was found in the way KVM implements its device control API. When a device is created via kvm_ioctl_create_device(), it holds a reference to a VM object. This reference is transferred to file descriptor table of the caller. If such file descriptor was closed, reference count to the VM object could become zero, which could lead to a use-after-free issue. A user/process could use this flaw to crash the guest VM resulting in a denial of service or, potentially, gain privileged access to a system.

  • A use-after-free vulnerability was found in the way KVM emulates a preemption timer for L2 guests when nested virtualization is enabled. A guest user/process could use this flaw to crash the host kernel resulting in a denial of service or, potentially, gain privileged access to a system.

  • It was discovered that a certain sequence of operations related to IPv4 routing could trigger a kernel memory leak. An attacker could potentially exploit that from a container to cause a denial of service.

Note that Tenable Network Security has extracted the preceding description block directly from the Virtuozzo security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

                                        
                                            #
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(133454);
  script_version("1.2");
  script_cvs_date("Date: 2020/02/07");

  script_cve_id(
    "CVE-2019-6974",
    "CVE-2019-7221"
  );

  script_name(english:"Virtuozzo 7 : readykernel-patch (VZA-2019-045)");
  script_summary(english:"Checks the readykernel output for the updated patch.");

  script_set_attribute(attribute:"synopsis", value:
"The remote Virtuozzo host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"According to the version of the vzkernel package and the
readykernel-patch installed, the Virtuozzo installation on the remote
host is affected by the following vulnerabilities :

  - A use-after-free vulnerability was found in the way KVM
    implements its device control API. When a device is
    created via kvm_ioctl_create_device(), it holds a
    reference to a VM object. This reference is transferred
    to file descriptor table of the caller. If such file
    descriptor was closed, reference count to the VM object
    could become zero, which could lead to a use-after-free
    issue. A user/process could use this flaw to crash the
    guest VM resulting in a denial of service or,
    potentially, gain privileged access to a system.

  - A use-after-free vulnerability was found in the way KVM
    emulates a preemption timer for L2 guests when nested
    virtualization is enabled. A guest user/process could
    use this flaw to crash the host kernel resulting in a
    denial of service or, potentially, gain privileged
    access to a system.

  - It was discovered that a certain sequence of operations
    related to IPv4 routing could trigger a kernel memory
    leak. An attacker could potentially exploit that from a
    container to cause a denial of service.

Note that Tenable Network Security has extracted the preceding
description block directly from the Virtuozzo 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://virtuozzosupport.force.com/s/article/VZA-2019-045");
  script_set_attribute(attribute:"see_also", value:"https://readykernel.com/patch/1524/");
  script_set_attribute(attribute:"see_also", value:"https://readykernel.com/patch/1526/");
  script_set_attribute(attribute:"solution", value:"Update the readykernel patch.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/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:H/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"patch_publication_date", value:"2019/06/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/02/04");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:virtuozzo:virtuozzo:readykernel");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:virtuozzo:virtuozzo:7");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}

include("global_settings.inc");
include("readykernel.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);

release = get_kb_item("Host/Virtuozzo/release");
if (isnull(release) || "Virtuozzo" >!< release) audit(AUDIT_OS_NOT, "Virtuozzo");
os_ver = pregmatch(pattern: "Virtuozzo Linux release ([0-9]+\.[0-9])(\D|$)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Virtuozzo");
os_ver = os_ver[1];
if (! preg(pattern:"^7([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Virtuozzo 7.x", "Virtuozzo " + os_ver);

if (!get_kb_item("Host/Virtuozzo/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, "Virtuozzo", cpu);

rk_info = get_kb_item("Host/readykernel-info");
if (empty_or_null(rk_info)) audit(AUDIT_UNKNOWN_APP_VER, "Virtuozzo");

checks = make_list2(
  make_array(
    "kernel","vzkernel-3.10.0-693.1.1.vz7.37.30",
    "patch","readykernel-patch-37.30-77.0-1.vl7"
  ),
  make_array(
    "kernel","vzkernel-3.10.0-693.11.6.vz7.40.4",
    "patch","readykernel-patch-40.4-77.0-1.vl7"
  )
);
readykernel_execute_checks(checks:checks, severity:SECURITY_WARNING, release:"Virtuozzo-7");