Vulnerabilities > CVE-2012-0943 - Permissions, Privileges, and Access Controls 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
robert-ancell
canonical
CWE-264
nessus
exploit available
NVD
Published: 2014-05-22
Updated: 2014-05-30

Summary

debian/guest-account in Light Display Manager (lightdm) 1.0.x before 1.0.6 and 1.1.x before 1.1.7, as used in Ubuntu Linux 11.10, allows local users to delete arbitrary files via a space in the name of a file in /tmp. NOTE: this identifier was SPLIT per ADT1/ADT2 due to different codebases and affected versions. CVE-2012-6648 has been assigned for the gdm-guest-session issue.

Vulnerable Configurations

Part Description Count
Application
Robert_Ancell
13
OS
Canonical
1

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Accessing, Modifying or Executing Executable Files
    An attack of this type exploits a system's configuration that allows an attacker to either directly access an executable file, for example through shell access; or in a possible worst case allows an attacker to upload a file and then execute it. Web servers, ftp servers, and message oriented middleware systems which have many integration points are particularly vulnerable, because both the programmers and the administrators must be in synch regarding the interfaces and the correct privileges for each interface.
  • Leverage Executable Code in Non-Executable Files
    An attack of this type exploits a system's trust in configuration and resource files, when the executable loads the resource (such as an image file or configuration file) the attacker has modified the file to either execute malicious code directly or manipulate the target process (e.g. application server) to execute based on the malicious configuration parameters. Since systems are increasingly interrelated mashing up resources from local and remote sources the possibility of this attack occurring is high. The attack can be directed at a client system, such as causing buffer overrun through loading seemingly benign image files, as in Microsoft Security Bulletin MS04-028 where specially crafted JPEG files could cause a buffer overrun once loaded into the browser. Another example targets clients reading pdf files. In this case the attacker simply appends javascript to the end of a legitimate url for a pdf (http://www.gnucitizen.org/blog/danger-danger-danger/) http://path/to/pdf/file.pdf#whatever_name_you_want=javascript:your_code_here The client assumes that they are reading a pdf, but the attacker has modified the resource and loaded executable javascript into the client's browser process. The attack can also target server processes. The attacker edits the resource or configuration file, for example a web.xml file used to configure security permissions for a J2EE app server, adding role name "public" grants all users with the public role the ability to use the administration functionality. The server trusts its configuration file to be correct, but when they are manipulated, the attacker gains full control.
  • Blue Boxing
    This type of attack against older telephone switches and trunks has been around for decades. A tone is sent by an adversary to impersonate a supervisor signal which has the effect of rerouting or usurping command of the line. While the US infrastructure proper may not contain widespread vulnerabilities to this type of attack, many companies are connected globally through call centers and business process outsourcing. These international systems may be operated in countries which have not upgraded Telco infrastructure and so are vulnerable to Blue boxing. Blue boxing is a result of failure on the part of the system to enforce strong authorization for administrative functions. While the infrastructure is different than standard current applications like web applications, there are historical lessons to be learned to upgrade the access control for administrative functions.
  • Restful Privilege Elevation
    Rest uses standard HTTP (Get, Put, Delete) style permissions methods, but these are not necessarily correlated generally with back end programs. Strict interpretation of HTTP get methods means that these HTTP Get services should not be used to delete information on the server, but there is no access control mechanism to back up this logic. This means that unless the services are properly ACL'd and the application's service implementation are following these guidelines then an HTTP request can easily execute a delete or update on the server side. The attacker identifies a HTTP Get URL such as http://victimsite/updateOrder, which calls out to a program to update orders on a database or other resource. The URL is not idempotent so the request can be submitted multiple times by the attacker, additionally, the attacker may be able to exploit the URL published as a Get method that actually performs updates (instead of merely retrieving data). This may result in malicious or inadvertent altering of data on the server.
  • Target Programs with Elevated Privileges
    This attack targets programs running with elevated privileges. The attacker would try to leverage a bug in the running program and get arbitrary code to execute with elevated privileges. For instance an attacker would look for programs that write to the system directories or registry keys (such as HKLM, which stores a number of critical Windows environment variables). These programs are typically running with elevated privileges and have usually not been designed with security in mind. Such programs are excellent exploit targets because they yield lots of power when they break. The malicious user try to execute its code at the same level as a privileged system call.

Exploit-Db

descriptionLightDM 1.0.6 Arbitrary File Deletion Vulnerability. CVE-2012-0943. Local exploit for linux platform
idEDB-ID:36966
last seen2016-02-04
modified2012-03-13
published2012-03-13
reporterRyan Lortie
sourcehttps://www.exploit-db.com/download/36966/
titleLightDM 1.0.6 Arbitrary File Deletion Vulnerability

Nessus

  • NASL familyUbuntu Local Security Checks
    NASL idUBUNTU_USN-1399-2.NASL
    descriptionRyan Lortie discovered that a guest session script bundled in the Light Display Manager package improperly cleaned out certain guest session files. A local attacker could use this issue to delete arbitrary files. 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 id58341
    published2012-03-14
    reporterUbuntu Security Notice (C) 2012-2019 Canonical, Inc. / NASL script (C) 2012-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/58341
    titleUbuntu 11.10 : lightdm vulnerability (USN-1399-2)
    code
    #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-1399-2. 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(58341);
  script_version("1.10");
  script_cvs_date("Date: 2019/09/19 12:54:27");

  script_cve_id("CVE-2012-0943");
  script_bugtraq_id(52452);
  script_xref(name:"USN", value:"1399-2");

  script_name(english:"Ubuntu 11.10 : lightdm vulnerability (USN-1399-2)");
  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:
"Ryan Lortie discovered that a guest session script bundled in the
Light Display Manager package improperly cleaned out certain guest
session files. A local attacker could use this issue to delete
arbitrary files.

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/1399-2/"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected lightdm package."
  );
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:lightdm");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:11.10");

  script_set_attribute(attribute:"vuln_publication_date", value:"2014/05/22");
  script_set_attribute(attribute:"patch_publication_date", value:"2012/03/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2012/03/14");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2012-2019 Canonical, Inc. / NASL script (C) 2012-2019 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:"^(11\.10)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 11.10", "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:"11.10", pkgname:"lightdm", pkgver:"1.0.6-0ubuntu1.6")) 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, "lightdm");
}
  • NASL familyUbuntu Local Security Checks
    NASL idUBUNTU_USN-1399-1.NASL
    descriptionRyan Lortie discovered that gdm-guest-session improperly cleaned out certain guest session files. A local attacker could use this issue to delete arbitrary files. 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 id58340
    published2012-03-14
    reporterUbuntu Security Notice (C) 2012-2019 Canonical, Inc. / NASL script (C) 2012-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/58340
    titleUbuntu 10.04 LTS / 10.10 / 11.04 : gdm-guest-session vulnerability (USN-1399-1)
    code
    #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-1399-1. 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(58340);
  script_version("1.10");
  script_cvs_date("Date: 2019/09/19 12:54:27");

  script_cve_id("CVE-2012-0943");
  script_bugtraq_id(52452);
  script_xref(name:"USN", value:"1399-1");

  script_name(english:"Ubuntu 10.04 LTS / 10.10 / 11.04 : gdm-guest-session vulnerability (USN-1399-1)");
  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:
"Ryan Lortie discovered that gdm-guest-session improperly cleaned out
certain guest session files. A local attacker could use this issue to
delete arbitrary files.

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/1399-1/"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected gdm-guest-session package."
  );
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:gdm-guest-session");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:10.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:10.10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:11.04");

  script_set_attribute(attribute:"vuln_publication_date", value:"2014/05/22");
  script_set_attribute(attribute:"patch_publication_date", value:"2012/03/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2012/03/14");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2012-2019 Canonical, Inc. / NASL script (C) 2012-2019 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:"^(10\.04|10\.10|11\.04)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 10.04 / 10.10 / 11.04", "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:"10.04", pkgname:"gdm-guest-session", pkgver:"0.15ubuntu0.1")) flag++;
if (ubuntu_check(osver:"10.10", pkgname:"gdm-guest-session", pkgver:"0.17ubuntu0.1")) flag++;
if (ubuntu_check(osver:"11.04", pkgname:"gdm-guest-session", pkgver:"0.24ubuntu0.1")) 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, "gdm-guest-session");
}

References