Vulnerabilities > CVE-2010-0832 - Link Following vulnerability in Canonical Ubuntu Linux 10.04/9.10

047910
CVSS 6.9 - MEDIUM
Attack vector
LOCAL
Attack complexity
MEDIUM
Privileges required
NONE
Confidentiality impact
COMPLETE
Integrity impact
COMPLETE
Availability impact
COMPLETE
local
canonical
CWE-59
nessus
exploit available
NVD
Published: 2010-07-12
Updated: 2017-08-17

Summary

pam_motd (aka the MOTD module) in libpam-modules before 1.1.0-2ubuntu1.1 in PAM on Ubuntu 9.10 and libpam-modules before 1.1.1-2ubuntu5 in PAM on Ubuntu 10.04 LTS allows local users to change the ownership of arbitrary files via a symlink attack on .cache in a user's home directory, related to "user file stamps" and the motd.legal-notice file.

Vulnerable Configurations

Part Description Count
OS
Canonical
2

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Symlink Attack
    An attacker positions a symbolic link in such a manner that the targeted user or application accesses the link's endpoint, assuming that it is accessing a file with the link's name. The endpoint file may be either output or input. If the file is output, the result is that the endpoint is modified, instead of a file at the intended location. Modifications to the endpoint file may include appending, overwriting, corrupting, changing permissions, or other modifications. In some variants of this attack the attacker may be able to control the change to a file while in other cases they cannot. The former is especially damaging since the attacker may be able to grant themselves increased privileges or insert false information, but the latter can also be damaging as it can expose sensitive information or corrupt or destroy vital system or application files. Alternatively, the endpoint file may serve as input to the targeted application. This can be used to feed malformed input into the target or to cause the target to process different information, possibly allowing the attacker to control the actions of the target or to cause the target to expose information to the attacker. Moreover, the actions taken on the endpoint file are undertaken with the permissions of the targeted user or application, which may exceed the permissions that the attacker would normally have.
  • 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.
  • Manipulating Input to File System Calls
    An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible.

Exploit-Db

  • descriptionUbuntu 9.10 (Karmic Koala) & 10.04 LTS (Lucid Lynx) PAM 1.1.0 MOTD - Local Root Exploit. CVE-2010-0832. Local exploit for linux platform
    idEDB-ID:14339
    last seen2016-02-01
    modified2010-07-12
    published2010-07-12
    reporteranonymous
    sourcehttps://www.exploit-db.com/download/14339/
    titleUbuntu 9.10 Karmic Koala & 10.04 LTS Lucid Lynx PAM 1.1.0 MOTD - Local Root Exploit
  • descriptionUbuntu PAM MOTD File Tampering (Privilege Escalation). CVE-2010-0832. Local exploit for linux platform
    fileexploits/linux/local/14273.sh
    idEDB-ID:14273
    last seen2016-02-01
    modified2010-07-08
    platformlinux
    port
    published2010-07-08
    reporterKristian Erik Hermansen
    sourcehttps://www.exploit-db.com/download/14273/
    titleUbuntu - PAM MOTD File Tampering Privilege Escalation
    typelocal

Nessus

  • NASL familyUbuntu Local Security Checks
    NASL idUBUNTU_USN-959-1.NASL
    descriptionDenis Excoffier discovered that the PAM MOTD module in Ubuntu did not correctly handle path permissions when creating user file stamps. A local attacker could exploit this to gain root privilieges. 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 id47679
    published2010-07-08
    reporterUbuntu Security Notice (C) 2010-2019 Canonical, Inc. / NASL script (C) 2010-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/47679
    titleUbuntu 9.10 / 10.04 LTS : pam vulnerability (USN-959-1)
    code
    #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-959-1. 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(47679);
  script_version("1.13");
  script_cvs_date("Date: 2019/09/19 12:54:26");

  script_cve_id("CVE-2010-0832");
  script_xref(name:"USN", value:"959-1");

  script_name(english:"Ubuntu 9.10 / 10.04 LTS : pam vulnerability (USN-959-1)");
  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:
"Denis Excoffier discovered that the PAM MOTD module in Ubuntu did not
correctly handle path permissions when creating user file stamps. A
local attacker could exploit this to gain root privilieges.

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/959-1/"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:M/Au:N/C:C/I:C/A:C");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"exploit_framework_core", value:"true");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam-cracklib");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam-runtime");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam0g");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam0g-dev");
  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:9.10");

  script_set_attribute(attribute:"vuln_publication_date", value:"2010/07/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2010/07/07");
  script_set_attribute(attribute:"plugin_publication_date", value:"2010/07/08");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2010-2019 Canonical, Inc. / NASL script (C) 2010-2019 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:"^(9\.10|10\.04)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 9.10 / 10.04", "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:"9.10", pkgname:"libpam-cracklib", pkgver:"1.1.0-2ubuntu1.1")) flag++;
if (ubuntu_check(osver:"9.10", pkgname:"libpam-doc", pkgver:"1.1.0-2ubuntu1.1")) flag++;
if (ubuntu_check(osver:"9.10", pkgname:"libpam-modules", pkgver:"1.1.0-2ubuntu1.1")) flag++;
if (ubuntu_check(osver:"9.10", pkgname:"libpam-runtime", pkgver:"1.1.0-2ubuntu1.1")) flag++;
if (ubuntu_check(osver:"9.10", pkgname:"libpam0g", pkgver:"1.1.0-2ubuntu1.1")) flag++;
if (ubuntu_check(osver:"9.10", pkgname:"libpam0g-dev", pkgver:"1.1.0-2ubuntu1.1")) flag++;
if (ubuntu_check(osver:"10.04", pkgname:"libpam-cracklib", pkgver:"1.1.1-2ubuntu5")) flag++;
if (ubuntu_check(osver:"10.04", pkgname:"libpam-doc", pkgver:"1.1.1-2ubuntu5")) flag++;
if (ubuntu_check(osver:"10.04", pkgname:"libpam-modules", pkgver:"1.1.1-2ubuntu5")) flag++;
if (ubuntu_check(osver:"10.04", pkgname:"libpam-runtime", pkgver:"1.1.1-2ubuntu5")) flag++;
if (ubuntu_check(osver:"10.04", pkgname:"libpam0g", pkgver:"1.1.1-2ubuntu5")) flag++;
if (ubuntu_check(osver:"10.04", pkgname:"libpam0g-dev", pkgver:"1.1.1-2ubuntu5")) 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, "libpam-cracklib / libpam-doc / libpam-modules / libpam-runtime / etc");
}
  • NASL familyUbuntu Local Security Checks
    NASL idUBUNTU_USN-959-2.NASL
    descriptionUSN-959-1 fixed vulnerabilities in PAM. This update provides the corresponding updates for Ubuntu 10.10. Denis Excoffier discovered that the PAM MOTD module in Ubuntu did not correctly handle path permissions when creating user file stamps. A local attacker could exploit this to gain root privilieges. 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 id50342
    published2010-10-26
    reporterUbuntu Security Notice (C) 2010-2019 Canonical, Inc. / NASL script (C) 2010-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/50342
    titleUbuntu 10.10 : pam vulnerability (USN-959-2)
    code
    #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-959-2. 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(50342);
  script_version("1.9");
  script_cvs_date("Date: 2019/09/19 12:54:26");

  script_cve_id("CVE-2010-0832");
  script_bugtraq_id(41465);
  script_xref(name:"USN", value:"959-2");

  script_name(english:"Ubuntu 10.10 : pam vulnerability (USN-959-2)");
  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-959-1 fixed vulnerabilities in PAM. This update provides the
corresponding updates for Ubuntu 10.10.

Denis Excoffier discovered that the PAM MOTD module in Ubuntu did not
correctly handle path permissions when creating user file stamps. A
local attacker could exploit this to gain root privilieges.

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/959-2/"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:M/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:F/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:"exploit_framework_core", value:"true");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam-cracklib");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam-runtime");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam0g");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam0g-dev");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:10.10");

  script_set_attribute(attribute:"vuln_publication_date", value:"2010/07/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2010/10/25");
  script_set_attribute(attribute:"plugin_publication_date", value:"2010/10/26");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2010-2019 Canonical, Inc. / NASL script (C) 2010-2019 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\.10)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 10.10", "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:"10.10", pkgname:"libpam-cracklib", pkgver:"1.1.1-4ubuntu2")) flag++;
if (ubuntu_check(osver:"10.10", pkgname:"libpam-doc", pkgver:"1.1.1-4ubuntu2")) flag++;
if (ubuntu_check(osver:"10.10", pkgname:"libpam-modules", pkgver:"1.1.1-4ubuntu2")) flag++;
if (ubuntu_check(osver:"10.10", pkgname:"libpam-runtime", pkgver:"1.1.1-4ubuntu2")) flag++;
if (ubuntu_check(osver:"10.10", pkgname:"libpam0g", pkgver:"1.1.1-4ubuntu2")) flag++;
if (ubuntu_check(osver:"10.10", pkgname:"libpam0g-dev", pkgver:"1.1.1-4ubuntu2")) 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, "libpam-cracklib / libpam-doc / libpam-modules / libpam-runtime / etc");
}

Packetstorm

Seebug

  • bulletinFamilyexploit
    descriptionNo description provided by source.
    idSSV:69376
    last seen2017-11-19
    modified2014-07-01
    published2014-07-01
    reporterRoot
    sourcehttps://www.seebug.org/vuldb/ssvid-69376
    titleUbuntu PAM 1.1.0 MOTD - Local Root Exploit
  • bulletinFamilyexploit
    descriptionNo description provided by source.
    idSSV:19936
    last seen2017-11-19
    modified2010-07-10
    published2010-07-10
    reporterRoot
    sourcehttps://www.seebug.org/vuldb/ssvid-19936
    titleUbuntu PAM MOTD File Tampering (Privilege Escalation)

References