Ubuntu 16.04 LTS / 18.04 LTS / 19.10 : apport vulnerabilities (USN-4315-1)

2020-04-02T00:00:00
ID UBUNTU_USN-4315-1.NASL
Type nessus
Reporter Ubuntu Security Notice (C) 2020 Canonical, Inc. / NASL script (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
Modified 2020-04-02T00:00:00

Description

Maximilien Bourgeteau discovered that the Apport lock file was created with insecure permissions. This could allow a local attacker to escalate their privileges via a symlink attack. (CVE-2020-8831)

Maximilien Bourgeteau discovered a race condition in Apport when setting crash report permissions. This could allow a local attacker to read arbitrary files via a symlink attack. (CVE-2020-8833).

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.

                                        
                                            #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-4315-1. 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(135171);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/05/04");

  script_cve_id("CVE-2020-8831", "CVE-2020-8833");
  script_xref(name:"USN", value:"4315-1");

  script_name(english:"Ubuntu 16.04 LTS / 18.04 LTS / 19.10 : apport vulnerabilities (USN-4315-1)");
  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:
"Maximilien Bourgeteau discovered that the Apport lock file was created
with insecure permissions. This could allow a local attacker to
escalate their privileges via a symlink attack. (CVE-2020-8831)

Maximilien Bourgeteau discovered a race condition in Apport when
setting crash report permissions. This could allow a local attacker to
read arbitrary files via a symlink attack. (CVE-2020-8833).

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/4315-1/"
  );
  script_set_attribute(
    attribute:"solution", 
    value:
"Update the affected apport, python-apport and / or python3-apport
packages."
  );
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:N/I:P/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:N/I:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-8831");
  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:apport");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python-apport");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python3-apport");
  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:19.10");

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/04/22");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/04/02");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/04/02");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2020 Canonical, Inc. / NASL script (C) 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:"^(16\.04|18\.04|19\.10)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 16.04 / 18.04 / 19.10", "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:"16.04", pkgname:"apport", pkgver:"2.20.1-0ubuntu2.23")) flag++;
if (ubuntu_check(osver:"16.04", pkgname:"python-apport", pkgver:"2.20.1-0ubuntu2.23")) flag++;
if (ubuntu_check(osver:"16.04", pkgname:"python3-apport", pkgver:"2.20.1-0ubuntu2.23")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"apport", pkgver:"2.20.9-0ubuntu7.14")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"python-apport", pkgver:"2.20.9-0ubuntu7.14")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"python3-apport", pkgver:"2.20.9-0ubuntu7.14")) flag++;
if (ubuntu_check(osver:"19.10", pkgname:"apport", pkgver:"2.20.11-0ubuntu8.8")) flag++;
if (ubuntu_check(osver:"19.10", pkgname:"python-apport", pkgver:"2.20.11-0ubuntu8.8")) flag++;
if (ubuntu_check(osver:"19.10", pkgname:"python3-apport", pkgver:"2.20.11-0ubuntu8.8")) 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, "apport / python-apport / python3-apport");
}