Vulnerabilities > CVE-2011-3632 - Link Following vulnerability in multiple products

047910
CVSS 7.1 - HIGH
Attack vector
LOCAL
Attack complexity
LOW
Privileges required
LOW
Confidentiality impact
HIGH
Integrity impact
HIGH
Availability impact
NONE
local
low complexity
hardlink-project
redhat
debian
CWE-59
nessus
NVD
Published: 2019-11-26
Updated: 2020-08-18

Summary

Hardlink before 0.1.2 operates on full file system objects path names which can allow a local attacker to use this flaw to conduct symlink attacks.

Vulnerable Configurations

Part Description Count
Application
Hardlink_Project
1
OS
Redhat
2
OS
Debian
3

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.

Nessus

  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2011-14753.NASL
    descriptionfix possible buffer overflows, integer overflows (CVE-2011-3630 CVE-2011-3631 CVE-2011-3632) Note that Tenable Network Security has extracted the preceding description block directly from the Fedora 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 id57069
    published2011-12-12
    reporterThis script is Copyright (C) 2011-2019 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/57069
    titleFedora 15 : hardlink-1.0-12.fc15 (2011-14753)
    code
    #%NASL_MIN_LEVEL 80502
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Fedora Security Advisory 2011-14753.
#

include("compat.inc");

if (description)
{
  script_id(57069);
  script_version("1.9");
  script_cvs_date("Date: 2019/08/02 13:32:34");

  script_cve_id("CVE-2011-3630", "CVE-2011-3631", "CVE-2011-3632");
  script_bugtraq_id(50805, 50808, 50809);
  script_xref(name:"FEDORA", value:"2011-14753");

  script_name(english:"Fedora 15 : hardlink-1.0-12.fc15 (2011-14753)");
  script_summary(english:"Checks rpm output for the updated package.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Fedora host is missing a security update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"fix possible buffer overflows, integer overflows (CVE-2011-3630
CVE-2011-3631 CVE-2011-3632)

Note that Tenable Network Security has extracted the preceding
description block directly from the Fedora 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://bugzilla.redhat.com/show_bug.cgi?id=746709"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.redhat.com/show_bug.cgi?id=746710"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.redhat.com/show_bug.cgi?id=746713"
  );
  # https://lists.fedoraproject.org/pipermail/package-announce/2011-December/070816.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?20615638"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected hardlink package."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:P");
  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:fedoraproject:fedora:hardlink");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:15");

  script_set_attribute(attribute:"patch_publication_date", value:"2011/10/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2011/12/12");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2011-2019 Tenable Network Security, Inc.");
  script_family(english:"Fedora Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list");

  exit(0);
}


include("audit.inc");
include("global_settings.inc");
include("rpm.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/RedHat/release");
if (isnull(release) || "Fedora" >!< release) audit(AUDIT_OS_NOT, "Fedora");
os_ver = eregmatch(pattern: "Fedora.*release ([0-9]+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Fedora");
os_ver = os_ver[1];
if (! ereg(pattern:"^15([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 15.x", "Fedora " + os_ver);

if (!get_kb_item("Host/RedHat/rpm-list")) 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, "Fedora", cpu);

flag = 0;
if (rpm_check(release:"FC15", reference:"hardlink-1.0-12.fc15")) flag++;


if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:rpm_report_get());
  else security_warning(0);
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "hardlink");
}
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2011-14727.NASL
    descriptionfix possible buffer overflows, integer overflows (CVE-2011-3630 CVE-2011-3631 CVE-2011-3632) Note that Tenable Network Security has extracted the preceding description block directly from the Fedora 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 id56933
    published2011-11-26
    reporterThis script is Copyright (C) 2011-2019 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/56933
    titleFedora 16 : hardlink-1.0-12.fc16 (2011-14727)
    code
    #%NASL_MIN_LEVEL 80502
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Fedora Security Advisory 2011-14727.
#

include("compat.inc");

if (description)
{
  script_id(56933);
  script_version("1.8");
  script_cvs_date("Date: 2019/08/02 13:32:34");

  script_cve_id("CVE-2011-3630", "CVE-2011-3631", "CVE-2011-3632");
  script_xref(name:"FEDORA", value:"2011-14727");

  script_name(english:"Fedora 16 : hardlink-1.0-12.fc16 (2011-14727)");
  script_summary(english:"Checks rpm output for the updated package.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Fedora host is missing a security update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"fix possible buffer overflows, integer overflows (CVE-2011-3630
CVE-2011-3631 CVE-2011-3632)

Note that Tenable Network Security has extracted the preceding
description block directly from the Fedora 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://bugzilla.redhat.com/show_bug.cgi?id=746709"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.redhat.com/show_bug.cgi?id=746710"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.redhat.com/show_bug.cgi?id=746713"
  );
  # https://lists.fedoraproject.org/pipermail/package-announce/2011-November/069675.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?92396801"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected hardlink package."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:P");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:hardlink");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:16");

  script_set_attribute(attribute:"patch_publication_date", value:"2011/10/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2011/11/26");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2011-2019 Tenable Network Security, Inc.");
  script_family(english:"Fedora Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list");

  exit(0);
}


include("audit.inc");
include("global_settings.inc");
include("rpm.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/RedHat/release");
if (isnull(release) || "Fedora" >!< release) audit(AUDIT_OS_NOT, "Fedora");
os_ver = eregmatch(pattern: "Fedora.*release ([0-9]+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Fedora");
os_ver = os_ver[1];
if (! ereg(pattern:"^16([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 16.x", "Fedora " + os_ver);

if (!get_kb_item("Host/RedHat/rpm-list")) 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, "Fedora", cpu);

flag = 0;
if (rpm_check(release:"FC16", reference:"hardlink-1.0-12.fc16")) flag++;


if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:rpm_report_get());
  else security_warning(0);
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "hardlink");
}

Seebug

bulletinFamilyexploit
descriptionBUGTRAQ ID: 50809 CVE ID: CVE-2011-3632 Linux是自由电脑操作系统内核。 Linux Kernel的hardlink工具在通过完整文件系统对象路径名称合并重复文件时存在本地权限提升漏洞，本地攻击者可利用此漏洞通过符号链接使用目标目录树之外的目录/文件上的hardlink，从而提升权限。 Linux kernel 2.6.x 厂商补丁： Linux ----- 目前厂商已经发布了升级补丁以修复这个安全问题，请到厂商的主页下载： http://www.kernel.org/
idSSV:24249
last seen2017-11-19
modified2011-11-25
published2011-11-25
reporterRoot
titleLinux Kernel hardlink工具符号链接攻击本地权限提升漏洞

References