Ubuntu 14.10 : linux regression (USN-2600-2)

2015-05-11T00:00:00
ID UBUNTU_USN-2600-2.NASL
Type nessus
Reporter Tenable
Modified 2016-10-26T00:00:00

Description

USN-2600-1 fixed vulnerabilities in the Linux kernel, however an unrelated regression in the auditing of some path names was introduced. Due to the regression the system could crash under certain conditions.

This update fixes the problem.

We apologize for the inconvenience.

A race condition between chown() and execve() was discovered in the Linux kernel. A local attacker could exploit this race by using chown on a setuid-user-binary to gain administrative privileges.

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-2600-2. 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(83334);
  script_version("$Revision: 2.4 $");
  script_cvs_date("$Date: 2016/10/26 14:16:27 $");

  script_bugtraq_id(74243);
  script_xref(name:"USN", value:"2600-2");

  script_name(english:"Ubuntu 14.10 : linux regression (USN-2600-2)");
  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:
"USN-2600-1 fixed vulnerabilities in the Linux kernel, however an
unrelated regression in the auditing of some path names was
introduced. Due to the regression the system could crash under certain
conditions.

This update fixes the problem.

We apologize for the inconvenience.

A race condition between chown() and execve() was discovered in the
Linux kernel. A local attacker could exploit this race by using chown
on a setuid-user-binary to gain administrative privileges.

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:"solution", 
    value:
"Update the affected linux-image-3.16-generic,
linux-image-3.16-generic-lpae and / or linux-image-3.16-lowlatency
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:ND/RL:OF/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:linux-image-3.16-generic");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-3.16-generic-lpae");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-3.16-lowlatency");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:14.10");

  script_set_attribute(attribute:"patch_publication_date", value:"2015/05/08");
  script_set_attribute(attribute:"plugin_publication_date", value:"2015/05/11");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2015-2016 Canonical, Inc. / NASL script (C) 2015-2016 Tenable Network Security, Inc.");
  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 (! ereg(pattern:"^(14\.10)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 14.10", "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:"14.10", pkgname:"linux-image-3.16.0-37-generic", pkgver:"3.16.0-37.51")) flag++;
if (ubuntu_check(osver:"14.10", pkgname:"linux-image-3.16.0-37-generic-lpae", pkgver:"3.16.0-37.51")) flag++;
if (ubuntu_check(osver:"14.10", pkgname:"linux-image-3.16.0-37-lowlatency", pkgver:"3.16.0-37.51")) 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, "linux-image-3.16-generic / linux-image-3.16-generic-lpae / etc");
}