Vulnerabilities > CVE-2017-6181 - Improper Input Validation vulnerability in Ruby-Lang Ruby 2.4.0

047910
CVSS 7.5 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
HIGH
network
low complexity
ruby-lang
CWE-20
nessus
NVD
Published: 2017-04-03
Updated: 2024-11-21

Summary

The parse_char_class function in regparse.c in the Onigmo (aka Oniguruma-mod) regular expression library, as used in Ruby 2.4.0, allows remote attackers to cause a denial of service (deep recursion and application crash) via a crafted regular expression.

Vulnerable Configurations

Part Description Count
Application
Ruby-Lang
1

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Buffer Overflow via Environment Variables
    This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
  • Server Side Include (SSI) Injection
    An attacker can use Server Side Include (SSI) Injection to send code to a web application that then gets executed by the web server. Doing so enables the attacker to achieve similar results to Cross Site Scripting, viz., arbitrary code execution and information disclosure, albeit on a more limited scale, since the SSI directives are nowhere near as powerful as a full-fledged scripting language. Nonetheless, the attacker can conveniently gain access to sensitive files, such as password files, and execute shell commands.
  • Cross Zone Scripting
    An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security. In a zone-based model, pages belong to one of a set of zones corresponding to the level of privilege assigned to that page. Pages in an untrusted zone would have a lesser level of access to the system and/or be restricted in the types of executable content it was allowed to invoke. In a cross-zone scripting attack, a page that should be assigned to a less privileged zone is granted the privileges of a more trusted zone. This can be accomplished by exploiting bugs in the browser, exploiting incorrect configuration in the zone controls, through a cross-site scripting attack that causes the attackers' content to be treated as coming from a more trusted page, or by leveraging some piece of system functionality that is accessible from both the trusted and less trusted zone. This attack differs from "Restful Privilege Escalation" in that the latter correlates to the inadequate securing of RESTful access methods (such as HTTP DELETE) on the server, while cross-zone scripting attacks the concept of security zones as implemented by a browser.
  • Cross Site Scripting through Log Files
    An attacker may leverage a system weakness where logs are susceptible to log injection to insert scripts into the system's logs. If these logs are later viewed by an administrator through a thin administrative interface and the log data is not properly HTML encoded before being written to the page, the attackers' scripts stored in the log will be executed in the administrative interface with potentially serious consequences. This attack pattern is really a combination of two other attack patterns: log injection and stored cross site scripting.
  • Command Line Execution through SQL Injection
    An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.

Nessus

  • NASL familyPhotonOS Local Security Checks
    NASL idPHOTONOS_PHSA-2017-0024_RUBY.NASL
    descriptionAn update of the ruby package has been released.
    last seen2020-03-17
    modified2019-02-07
    plugin id121714
    published2019-02-07
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/121714
    titlePhoton OS 1.0: Ruby PHSA-2017-0024
    code
    #
# (C) Tenable Network Security, Inc.
#


# The descriptive text and package checks in this plugin were
# extracted from VMware Security Advisory PHSA-2017-0024. The text
# itself is copyright (C) VMware, Inc.


include('compat.inc');

if (description)
{
  script_id(121714);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2019/02/07");

  script_cve_id("CVE-2017-6181");

  script_name(english:"Photon OS 1.0: Ruby PHSA-2017-0024");
  script_summary(english:"Checks the rpm output for the updated packages.");

  script_set_attribute(attribute:"synopsis", value:
"The remote PhotonOS host is missing multiple security updates.");
  script_set_attribute(attribute:"description", value:
"An update of the ruby package has been released.");
  script_set_attribute(attribute:"see_also", value:"https://github.com/vmware/photon/wiki/Security-Updates-54.md");
  script_set_attribute(attribute:"solution", value:
"Update the affected Linux packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2017-10685");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/07/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/07/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/02/07");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:vmware:photonos:ruby");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:vmware:photonos:1.0");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"PhotonOS Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/PhotonOS/release", "Host/PhotonOS/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/PhotonOS/release");
if (isnull(release) || release !~ "^VMware Photon") audit(AUDIT_OS_NOT, "PhotonOS");
if (release !~ "^VMware Photon (?:Linux|OS) 1\.0(\D|$)") audit(AUDIT_OS_NOT, "PhotonOS 1.0");

if (!get_kb_item("Host/PhotonOS/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, "PhotonOS", cpu);

flag = 0;

if (rpm_check(release:"PhotonOS-1.0", reference:"ruby-2.4.0-4.ph1")) flag++;
if (rpm_check(release:"PhotonOS-1.0", reference:"ruby-debuginfo-2.4.0-4.ph1")) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "ruby");
}
  • NASL familyPhotonOS Local Security Checks
    NASL idPHOTONOS_PHSA-2017-0024.NASL
    descriptionAn update of [ncurses,openldap,libxml2,ruby] packages for PhotonOS has been released.
    last seen2019-02-21
    modified2019-02-07
    plugin id111873
    published2018-08-17
    reporterTenable
    sourcehttps://www.tenable.com/plugins/index.php?view=single&id=111873
    titlePhoton OS 1.0: Libxml2 / Ncurses / Openldap / Ruby PHSA-2017-0024 (deprecated)
    code
    #
# (C) Tenable Network Security, Inc.
#
# @DEPRECATED@
#
# Disabled on 2/7/2019
#

# The descriptive text and package checks in this plugin were
# extracted from VMware Security Advisory PHSA-2017-0024. The text
# itself is copyright (C) VMware, Inc.

include("compat.inc");

if (description)
{
  script_id(111873);
  script_version("1.2");
  script_cvs_date("Date: 2019/02/07 18:59:50");

  script_cve_id(
    "CVE-2017-6181",
    "CVE-2017-9047",
    "CVE-2017-9048",
    "CVE-2017-9049",
    "CVE-2017-9050",
    "CVE-2017-9287",
    "CVE-2017-10684",
    "CVE-2017-10685"
  );

  script_name(english:"Photon OS 1.0: Libxml2 / Ncurses / Openldap / Ruby PHSA-2017-0024 (deprecated)");
  script_summary(english:"Checks the rpm output for the updated packages.");

  script_set_attribute(attribute:"synopsis", value:
"This plugin has been deprecated.");
  script_set_attribute(attribute:"description", value:
"An update of [ncurses,openldap,libxml2,ruby] packages for PhotonOS has
been released.");
  # https://github.com/vmware/photon/wiki/Security-Updates-54
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?e51e1258");
  script_set_attribute(attribute:"solution", value:"n/a.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2017-10684");

  script_set_attribute(attribute:"patch_publication_date", value:"2017/07/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/08/17");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:vmware:photonos:libxml2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:vmware:photonos:ncurses");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:vmware:photonos:openldap");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:vmware:photonos:ruby");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:vmware:photonos:1.0");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"PhotonOS Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}

exit(0, "This plugin has been deprecated.");

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/PhotonOS/release");
if (isnull(release) || release !~ "^VMware Photon") audit(AUDIT_OS_NOT, "PhotonOS");
if (release !~ "^VMware Photon (?:Linux|OS) 1\.0(\D|$)") audit(AUDIT_OS_NOT, "PhotonOS 1.0");

if (!get_kb_item("Host/PhotonOS/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, "PhotonOS", cpu);

flag = 0;

pkgs = [
  "libxml2-2.9.4-6.ph1",
  "libxml2-debuginfo-2.9.4-6.ph1",
  "libxml2-devel-2.9.4-6.ph1",
  "libxml2-python-2.9.4-6.ph1",
  "ncurses-6.0-5.ph1",
  "ncurses-compat-6.0-5.ph1",
  "ncurses-debuginfo-6.0-5.ph1",
  "ncurses-devel-6.0-5.ph1",
  "openldap-2.4.43-3.ph1",
  "openldap-debuginfo-2.4.43-3.ph1",
  "ruby-2.4.0-4.ph1",
  "ruby-debuginfo-2.4.0-4.ph1"
];

foreach (pkg in pkgs)
  if (rpm_check(release:"PhotonOS-1.0", reference:pkg)) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "libxml2 / ncurses / openldap / ruby");
}

References