Vulnerabilities > CVE-2011-3628 - Unspecified vulnerability in Canonical Libpam-Modules and Ubuntu Linux

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
nessus

Summary

Untrusted search path vulnerability in pam_motd (aka the MOTD module) in libpam-modules before 1.1.3-2ubuntu2.1 on Ubuntu 11.10, before 1.1.2-2ubuntu8.4 on Ubuntu 11.04, before 1.1.1-4ubuntu2.4 on Ubuntu 10.10, before 1.1.1-2ubuntu5.4 on Ubuntu 10.04 LTS, and before 0.99.7.1-5ubuntu6.5 on Ubuntu 8.04 LTS, when using certain configurations such as "session optional pam_motd.so", allows local users to gain privileges by modifying the PATH environment variable to reference a malicious command, as demonstrated via uname. Per: http://cwe.mitre.org/data/definitions/426.html "CWE-426: Untrusted Search Path"

Nessus

NASL familyUbuntu Local Security Checks
NASL idUBUNTU_USN-1237-1.NASL
descriptionKees Cook discovered that the PAM pam_env module incorrectly handled certain malformed environment files. A local attacker could use this flaw to cause a denial of service, or possibly gain privileges. The default compiler options for affected releases should reduce the vulnerability to a denial of service. (CVE-2011-3148) Kees Cook discovered that the PAM pam_env module incorrectly handled variable expansion. A local attacker could use this flaw to cause a denial of service. (CVE-2011-3149) Stephane Chazelas discovered that the PAM pam_motd module incorrectly cleaned the environment during execution of the motd scripts. In certain environments, a local attacker could use this to execute arbitrary code as root, and gain 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.
last seen2020-06-01
modified2020-06-02
plugin id56629
published2011-10-25
reporterUbuntu Security Notice (C) 2011-2019 Canonical, Inc. / NASL script (C) 2011-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/56629
titleUbuntu 8.04 LTS / 10.04 LTS / 10.10 / 11.04 / 11.10 : pam vulnerabilities (USN-1237-1)
code
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-1237-1. 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(56629);
  script_version("1.12");
  script_cvs_date("Date: 2019/09/19 12:54:27");

  script_cve_id("CVE-2011-3148", "CVE-2011-3149", "CVE-2011-3628");
  script_xref(name:"USN", value:"1237-1");

  script_name(english:"Ubuntu 8.04 LTS / 10.04 LTS / 10.10 / 11.04 / 11.10 : pam vulnerabilities (USN-1237-1)");
  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:
"Kees Cook discovered that the PAM pam_env module incorrectly handled
certain malformed environment files. A local attacker could use this
flaw to cause a denial of service, or possibly gain privileges. The
default compiler options for affected releases should reduce the
vulnerability to a denial of service. (CVE-2011-3148)

Kees Cook discovered that the PAM pam_env module incorrectly handled
variable expansion. A local attacker could use this flaw to cause a
denial of service. (CVE-2011-3149)

Stephane Chazelas discovered that the PAM pam_motd module incorrectly
cleaned the environment during execution of the motd scripts. In
certain environments, a local attacker could use this to execute
arbitrary code as root, and gain 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:"see_also",
    value:"https://usn.ubuntu.com/1237-1/"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected libpam-modules package."
  );
  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:U/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:libpam-modules");
  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:"cpe", value:"cpe:/o:canonical:ubuntu_linux:11.10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:8.04:-:lts");

  script_set_attribute(attribute:"vuln_publication_date", value:"2012/07/22");
  script_set_attribute(attribute:"patch_publication_date", value:"2011/10/24");
  script_set_attribute(attribute:"plugin_publication_date", value:"2011/10/25");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2011-2019 Canonical, Inc. / NASL script (C) 2011-2019 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:"^(8\.04|10\.04|10\.10|11\.04|11\.10)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 8.04 / 10.04 / 10.10 / 11.04 / 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:"8.04", pkgname:"libpam-modules", pkgver:"0.99.7.1-5ubuntu6.5")) flag++;
if (ubuntu_check(osver:"10.04", pkgname:"libpam-modules", pkgver:"1.1.1-2ubuntu5.4")) flag++;
if (ubuntu_check(osver:"10.10", pkgname:"libpam-modules", pkgver:"1.1.1-4ubuntu2.4")) flag++;
if (ubuntu_check(osver:"11.04", pkgname:"libpam-modules", pkgver:"1.1.2-2ubuntu8.4")) flag++;
if (ubuntu_check(osver:"11.10", pkgname:"libpam-modules", pkgver:"1.1.3-2ubuntu2.1")) 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-modules");
}