Vulnerabilities > CVE-2017-6512 - Race Condition vulnerability in multiple products

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3625-1. 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(109086);
  script_version("1.5");
  script_cvs_date("Date: 2019/09/18 12:31:48");

  script_cve_id("CVE-2015-8853", "CVE-2016-6185", "CVE-2017-6512", "CVE-2018-6797", "CVE-2018-6798", "CVE-2018-6913");
  script_xref(name:"USN", value:"3625-1");

  script_name(english:"Ubuntu 14.04 LTS / 16.04 LTS / 17.10 : perl vulnerabilities (USN-3625-1)");
  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:
"It was discovered that Perl incorrectly handled certain regular
expressions. An attacker could possibly use this issue to cause Perl
to hang, resulting in a denial of service. This issue only affected
Ubuntu 14.04 LTS. (CVE-2015-8853)

It was discovered that Perl incorrectly loaded libraries from the
current working directory. A local attacker could possibly use this
issue to execute arbitrary code. This issue only affected Ubuntu 14.04
LTS and Ubuntu 16.04 LTS. (CVE-2016-6185)

It was discovered that Perl incorrectly handled the rmtree and
remove_tree functions. A local attacker could possibly use this issue
to set the mode on arbitrary files. This issue only affected Ubuntu
14.04 LTS and Ubuntu 16.04 LTS. (CVE-2017-6512)

Brian Carpenter discovered that Perl incorrectly handled certain
regular expressions. An attacker could use this issue to cause Perl to
crash, resulting in a denial of service, or possibly execute arbitrary
code. This issue has only been addressed in Ubuntu 16.04 LTS and
Ubuntu 17.10. (CVE-2018-6797)

Nguyen Duc Manh discovered that Perl incorrectly handled certain
regular expressions. An attacker could use this issue to cause Perl to
crash, resulting in a denial of service. This issue only affected
Ubuntu 16.04 LTS and Ubuntu 17.10. (CVE-2018-6798)

GwanYeong Kim discovered that Perl incorrectly handled certain data
when using the pack function. An attacker could use this issue to
cause Perl to crash, resulting in a denial of service, or possibly
execute arbitrary code. (CVE-2018-6913).

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/3625-1/"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected perl package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:perl");
  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:17.10");

  script_set_attribute(attribute:"vuln_publication_date", value:"2016/05/25");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/04/16");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/04/17");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2018-2019 Canonical, Inc. / NASL script (C) 2018-2019 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:"^(14\.04|16\.04|17\.10)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 14.04 / 16.04 / 17.10", "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:"perl", pkgver:"5.18.2-2ubuntu1.4")) flag++;
if (ubuntu_check(osver:"16.04", pkgname:"perl", pkgver:"5.22.1-9ubuntu0.3")) flag++;
if (ubuntu_check(osver:"17.10", pkgname:"perl", pkgver:"5.26.0-8ubuntu1.1")) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    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, "perl");
}