Vulnerabilities > CVE-2016-1581 - Improper Access Control vulnerability in Canonical LXD and Ubuntu Linux

047910
CVSS 5.5 - MEDIUM
Attack vector
LOCAL
Attack complexity
LOW
Privileges required
LOW
Confidentiality impact
HIGH
Integrity impact
NONE
Availability impact
NONE
local
low complexity
canonical
CWE-284
nessus

Summary

LXD before 2.0.2 uses world-readable permissions for /var/lib/lxd/zfs.img when setting up a loop based ZFS pool, which allows local users to copy and read data from arbitrary containers via unspecified vectors.

Vulnerable Configurations

Part Description Count
OS
Canonical
2
Application
Canonical
1

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Embedding Scripts within Scripts
    An attack of this type exploits a programs' vulnerabilities that are brought on by allowing remote hosts to execute scripts. The attacker leverages this capability to execute scripts to execute his/her own script by embedding it within other scripts that the target software is likely to execute. The attacker must have the ability to inject script into script that is likely to be executed. If this is done, then the attacker can potentially launch a variety of probes and attacks against the web server's local environment, in many cases the so-called DMZ, back end resources the web server can communicate with, and other hosts. With the proliferation of intermediaries, such as Web App Firewalls, network devices, and even printers having JVMs and Web servers, there are many locales where an attacker can inject malicious scripts. Since this attack pattern defines scripts within scripts, there are likely privileges to execute said attack on the host. Of course, these attacks are not solely limited to the server side, client side scripts like Ajax and client side JavaScript can contain malicious scripts as well. In general all that is required is for there to be sufficient privileges to execute a script, but not protected against writing.
  • Signature Spoofing by Key Theft
    An attacker obtains an authoritative or reputable signer's private signature key by theft and then uses this key to forge signatures from the original signer to mislead a victim into performing actions that benefit the attacker.

Nessus

NASL familyUbuntu Local Security Checks
NASL idUBUNTU_USN-2988-1.NASL
descriptionRobie Basak discovered that LXD incorrectly set permissions when setting up a loop based ZFS pool. A local attacker could use this issue to copy and read the data of any LXD container. (CVE-2016-1581) Robie Basak discovered that LXD incorrectly set permissions when switching an unprivileged container into privileged mode. A local attacker could use this issue to access any world readable path in the container directory, including setuid binaries. (CVE-2016-1582). 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 id91424
published2016-06-01
reporterUbuntu Security Notice (C) 2016-2019 Canonical, Inc. / NASL script (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/91424
titleUbuntu 15.10 / 16.04 LTS : lxd vulnerabilities (USN-2988-1)
code
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-2988-1. 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(91424);
  script_version("2.7");
  script_cvs_date("Date: 2019/09/18 12:31:45");

  script_cve_id("CVE-2016-1581", "CVE-2016-1582");
  script_xref(name:"USN", value:"2988-1");

  script_name(english:"Ubuntu 15.10 / 16.04 LTS : lxd vulnerabilities (USN-2988-1)");
  script_summary(english:"Checks dpkg output for updated package.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Ubuntu host is missing a security-related patch."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"Robie Basak discovered that LXD incorrectly set permissions when
setting up a loop based ZFS pool. A local attacker could use this
issue to copy and read the data of any LXD container. (CVE-2016-1581)

Robie Basak discovered that LXD incorrectly set permissions when
switching an unprivileged container into privileged mode. A local
attacker could use this issue to access any world readable path in the
container directory, including setuid binaries. (CVE-2016-1582).

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/2988-1/"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected lxd package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:P/I:N/A:N");
  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:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:lxd");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:15.10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04");

  script_set_attribute(attribute:"vuln_publication_date", value:"2016/06/09");
  script_set_attribute(attribute:"patch_publication_date", value:"2016/05/31");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/06/01");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2016-2019 Canonical, Inc. / NASL script (C) 2016-2019 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:"^(15\.10|16\.04)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 15.10 / 16.04", "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:"15.10", pkgname:"lxd", pkgver:"0.20-0ubuntu4.2")) flag++;
if (ubuntu_check(osver:"16.04", pkgname:"lxd", pkgver:"2.0.2-0ubuntu1~16.04.1")) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_NOTE,
    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, "lxd");
}