Vulnerabilities > CVE-2018-20124 - Out-of-bounds Read vulnerability in multiple products

047910
CVSS 2.1 - LOW
Attack vector
LOCAL
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
PARTIAL
local
low complexity
qemu
canonical
CWE-125
nessus

Summary

hw/rdma/rdma_backend.c in QEMU allows guest OS users to trigger out-of-bounds access via a PvrdmaSqWqe ring element with a large num_sge value.

Vulnerable Configurations

Part Description Count
Application
Qemu
184
OS
Canonical
4

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Overread Buffers
    An adversary attacks a target by providing input that causes an application to read beyond the boundary of a defined buffer. This typically occurs when a value influencing where to start or stop reading is set to reflect positions outside of the valid memory location of the buffer. This type of attack may result in exposure of sensitive information, a system crash, or arbitrary code execution.

Nessus

NASL familyUbuntu Local Security Checks
NASL idUBUNTU_USN-3923-1.NASL
descriptionMichael Hanselmann discovered that QEMU incorrectly handled the Media Transfer Protocol (MTP). An attacker inside the guest could use this issue to read or write arbitrary files and cause a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 18.10. (CVE-2018-16867) Michael Hanselmann discovered that QEMU incorrectly handled the Media Transfer Protocol (MTP). An attacker inside the guest could use this issue to read arbitrary files, contrary to expectations. This issue only affected Ubuntu 18.04 LTS and Ubuntu 18.10. (CVE-2018-16872) Zhibin Hu discovered that QEMU incorrectly handled the Plan 9 File System support. An attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service. (CVE-2018-19489) Li Quang and Saar Amar discovered multiple issues in the QEMU PVRDMA device. An attacker inside the guest could use these issues to cause a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 18.10. These issues were resolved by disabling PVRDMA support in Ubuntu 18.10. (CVE-2018-20123, CVE-2018-20124, CVE-2018-20125, CVE-2018-20126, CVE-2018-20191, CVE-2018-20216) Michael Hanselmann discovered that QEMU incorrectly handled certain i2c commands. A local attacker could possibly use this issue to read QEMU process memory. This issue only affected Ubuntu 18.04 LTS and Ubuntu 18.10. (CVE-2019-3812) It was discovered that QEMU incorrectly handled the Slirp networking back-end. An attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service, or possibly execute arbitrary code on the host. In the default installation, when QEMU is used with libvirt, attackers would be isolated by the libvirt AppArmor profile. (CVE-2019-6778). Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
last seen2020-06-01
modified2020-06-02
plugin id123457
published2019-03-28
reporterUbuntu Security Notice (C) 2019-2020 Canonical, Inc. / NASL script (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/123457
titleUbuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 18.10 : qemu vulnerabilities (USN-3923-1)
code
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3923-1. The text 
# itself is copyright (C) Canonical, Inc. See 
# <http://www.ubuntu.com/usn/>. Ubuntu(R) is a registered 
# trademark of Canonical, Inc.
#

include("compat.inc");

if (description)
{
  script_id(123457);
  script_version("1.3");
  script_cvs_date("Date: 2020/01/27");

  script_cve_id("CVE-2018-16867", "CVE-2018-16872", "CVE-2018-19489", "CVE-2018-20123", "CVE-2018-20124", "CVE-2018-20125", "CVE-2018-20126", "CVE-2018-20191", "CVE-2018-20216", "CVE-2019-3812", "CVE-2019-6778");
  script_xref(name:"USN", value:"3923-1");

  script_name(english:"Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 18.10 : qemu vulnerabilities (USN-3923-1)");
  script_summary(english:"Checks dpkg output for updated packages.");

  script_set_attribute(
    attribute:"synopsis", 
    value:
"The remote Ubuntu host is missing one or more security-related
patches."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"Michael Hanselmann discovered that QEMU incorrectly handled the Media
Transfer Protocol (MTP). An attacker inside the guest could use this
issue to read or write arbitrary files and cause a denial of service,
or possibly execute arbitrary code. This issue only affected Ubuntu
18.10. (CVE-2018-16867)

Michael Hanselmann discovered that QEMU incorrectly handled the Media
Transfer Protocol (MTP). An attacker inside the guest could use this
issue to read arbitrary files, contrary to expectations. This issue
only affected Ubuntu 18.04 LTS and Ubuntu 18.10. (CVE-2018-16872)

Zhibin Hu discovered that QEMU incorrectly handled the Plan 9 File
System support. An attacker inside the guest could use this issue to
cause QEMU to crash, resulting in a denial of service.
(CVE-2018-19489)

Li Quang and Saar Amar discovered multiple issues in the QEMU PVRDMA
device. An attacker inside the guest could use these issues to cause a
denial of service, or possibly execute arbitrary code. This issue only
affected Ubuntu 18.10. These issues were resolved by disabling PVRDMA
support in Ubuntu 18.10. (CVE-2018-20123, CVE-2018-20124,
CVE-2018-20125, CVE-2018-20126, CVE-2018-20191, CVE-2018-20216)

Michael Hanselmann discovered that QEMU incorrectly handled certain
i2c commands. A local attacker could possibly use this issue to read
QEMU process memory. This issue only affected Ubuntu 18.04 LTS and
Ubuntu 18.10. (CVE-2019-3812)

It was discovered that QEMU incorrectly handled the Slirp networking
back-end. An attacker inside the guest could use this issue to cause
QEMU to crash, resulting in a denial of service, or possibly execute
arbitrary code on the host. In the default installation, when QEMU is
used with libvirt, attackers would be isolated by the libvirt AppArmor
profile. (CVE-2019-6778).

Note that Tenable Network Security has extracted the preceding
description block directly from the Ubuntu 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://usn.ubuntu.com/3923-1/"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/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:L/AC:L/PR:L/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-2019-6778");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:qemu-system");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:qemu-system-aarch64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:qemu-system-arm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:qemu-system-data");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:qemu-system-gui");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:qemu-system-mips");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:qemu-system-misc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:qemu-system-ppc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:qemu-system-s390x");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:qemu-system-sparc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:qemu-system-x86");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:14.04");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04");
  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:18.10");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/12/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/03/27");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/03/28");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2019-2020 Canonical, Inc. / NASL script (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Ubuntu Local Security Checks");

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

  exit(0);
}


include("audit.inc");
include("ubuntu.inc");
include("misc_func.inc");

if ( ! get_kb_item("Host/local_checks_enabled") ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/Ubuntu/release");
if ( isnull(release) ) audit(AUDIT_OS_NOT, "Ubuntu");
release = chomp(release);
if (! preg(pattern:"^(14\.04|16\.04|18\.04|18\.10)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 14.04 / 16.04 / 18.04 / 18.10", "Ubuntu " + release);
if ( ! get_kb_item("Host/Debian/dpkg-l") ) 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, "Ubuntu", cpu);

flag = 0;

if (ubuntu_check(osver:"14.04", pkgname:"qemu-system", pkgver:"2.0.0+dfsg-2ubuntu1.45")) flag++;
if (ubuntu_check(osver:"14.04", pkgname:"qemu-system-aarch64", pkgver:"2.0.0+dfsg-2ubuntu1.45")) flag++;
if (ubuntu_check(osver:"14.04", pkgname:"qemu-system-arm", pkgver:"2.0.0+dfsg-2ubuntu1.45")) flag++;
if (ubuntu_check(osver:"14.04", pkgname:"qemu-system-mips", pkgver:"2.0.0+dfsg-2ubuntu1.45")) flag++;
if (ubuntu_check(osver:"14.04", pkgname:"qemu-system-misc", pkgver:"2.0.0+dfsg-2ubuntu1.45")) flag++;
if (ubuntu_check(osver:"14.04", pkgname:"qemu-system-ppc", pkgver:"2.0.0+dfsg-2ubuntu1.45")) flag++;
if (ubuntu_check(osver:"14.04", pkgname:"qemu-system-sparc", pkgver:"2.0.0+dfsg-2ubuntu1.45")) flag++;
if (ubuntu_check(osver:"14.04", pkgname:"qemu-system-x86", pkgver:"2.0.0+dfsg-2ubuntu1.45")) flag++;
if (ubuntu_check(osver:"16.04", pkgname:"qemu-system", pkgver:"1:2.5+dfsg-5ubuntu10.36")) flag++;
if (ubuntu_check(osver:"16.04", pkgname:"qemu-system-aarch64", pkgver:"1:2.5+dfsg-5ubuntu10.36")) flag++;
if (ubuntu_check(osver:"16.04", pkgname:"qemu-system-arm", pkgver:"1:2.5+dfsg-5ubuntu10.36")) flag++;
if (ubuntu_check(osver:"16.04", pkgname:"qemu-system-mips", pkgver:"1:2.5+dfsg-5ubuntu10.36")) flag++;
if (ubuntu_check(osver:"16.04", pkgname:"qemu-system-misc", pkgver:"1:2.5+dfsg-5ubuntu10.36")) flag++;
if (ubuntu_check(osver:"16.04", pkgname:"qemu-system-ppc", pkgver:"1:2.5+dfsg-5ubuntu10.36")) flag++;
if (ubuntu_check(osver:"16.04", pkgname:"qemu-system-s390x", pkgver:"1:2.5+dfsg-5ubuntu10.36")) flag++;
if (ubuntu_check(osver:"16.04", pkgname:"qemu-system-sparc", pkgver:"1:2.5+dfsg-5ubuntu10.36")) flag++;
if (ubuntu_check(osver:"16.04", pkgname:"qemu-system-x86", pkgver:"1:2.5+dfsg-5ubuntu10.36")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"qemu-system", pkgver:"1:2.11+dfsg-1ubuntu7.12")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"qemu-system-arm", pkgver:"1:2.11+dfsg-1ubuntu7.12")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"qemu-system-mips", pkgver:"1:2.11+dfsg-1ubuntu7.12")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"qemu-system-misc", pkgver:"1:2.11+dfsg-1ubuntu7.12")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"qemu-system-ppc", pkgver:"1:2.11+dfsg-1ubuntu7.12")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"qemu-system-s390x", pkgver:"1:2.11+dfsg-1ubuntu7.12")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"qemu-system-sparc", pkgver:"1:2.11+dfsg-1ubuntu7.12")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"qemu-system-x86", pkgver:"1:2.11+dfsg-1ubuntu7.12")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"qemu-system", pkgver:"1:2.12+dfsg-3ubuntu8.6")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"qemu-system-arm", pkgver:"1:2.12+dfsg-3ubuntu8.6")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"qemu-system-data", pkgver:"1:2.12+dfsg-3ubuntu8.6")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"qemu-system-gui", pkgver:"1:2.12+dfsg-3ubuntu8.6")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"qemu-system-mips", pkgver:"1:2.12+dfsg-3ubuntu8.6")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"qemu-system-misc", pkgver:"1:2.12+dfsg-3ubuntu8.6")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"qemu-system-ppc", pkgver:"1:2.12+dfsg-3ubuntu8.6")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"qemu-system-s390x", pkgver:"1:2.12+dfsg-3ubuntu8.6")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"qemu-system-sparc", pkgver:"1:2.12+dfsg-3ubuntu8.6")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"qemu-system-x86", pkgver:"1:2.12+dfsg-3ubuntu8.6")) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : ubuntu_report_get()
  );
  exit(0);
}
else
{
  tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "qemu-system / qemu-system-aarch64 / qemu-system-arm / etc");
}