Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS : Git vulnerability (USN-3791-1) - Nessus

Critical   Plugin ID: 118083

This page contains detailed information about the Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS : Git vulnerability (USN-3791-1) Nessus plugin including available exploits and PoCs found on GitHub, in Metasploit or Exploit-DB for verifying of this vulnerability.

Plugin Overview


ID: 118083
Name: Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS : Git vulnerability (USN-3791-1)
Filename: ubuntu_USN-3791-1.nasl
Vulnerability Published: 2018-10-06
This Plugin Published: 2018-10-12
Last Modification Time: 2020-09-17
Plugin Version: 1.6
Plugin Type: local
Plugin Family: Ubuntu Local Security Checks
Dependencies: ssh_get_info.nasl
Required KB Items [?]: Host/cpu, Host/Debian/dpkg-l, Host/Ubuntu, Host/Ubuntu/release

Vulnerability Information


Severity: Critical
Vulnerability Published: 2018-10-06
Patch Published: 2018-10-12
CVE [?]: CVE-2018-17456
CPE [?]: cpe:/o:canonical:ubuntu_linux:14.04, cpe:/o:canonical:ubuntu_linux:16.04, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:git

Synopsis

The remote Ubuntu host is missing a security-related patch.

Description

It was discovered that git did not properly validate git submodule urls or paths. A remote attacker could possibly use this to craft a git repository that causes arbitrary code execution when recursive operations are used.

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.

Solution

Update the affected git package.

Public Exploits


Target Network Port(s): N/A
Target Asset(s): N/A
Exploit Available: True (Metasploit Framework, Exploit-DB, GitHub)
Exploit Ease: Exploits are available

Here's the list of publicly known exploits and PoCs for verifying the Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS : Git vulnerability (USN-3791-1) vulnerability:

  1. Metasploit: exploit/multi/http/git_submodule_url_exec
    [Malicious Git HTTP Server For CVE-2018-17456]
  2. Exploit-DB: exploits/linux/local/45548.txt
    [EDB-45548: Git Submodule - Arbitrary Code Execution (PoC)]
  3. Exploit-DB: exploits/linux/local/45631.md
    [EDB-45631: Git Submodule - Arbitrary Code Execution]
  4. GitHub: https://github.com/799600966/CVE-2018-17456
    [CVE-2018-17456]
  5. GitHub: https://github.com/AnonymKing/CVE-2017-1000117
    [CVE-2018-17456]
  6. GitHub: https://github.com/KorayAgaya/TrivyWeb
    [CVE-2018-17456]
  7. GitHub: https://github.com/matlink/CVE-2018-17456
    [CVE-2018-17456]
  8. GitHub: https://github.com/shpik-kr/CVE-2018-17456
    [CVE-2018-17456: 1-day]
  9. GitHub: https://github.com/siddharthraopotukuchi/trivy
    [CVE-2018-17456]
  10. GitHub: https://github.com/simiyo/trivy
    [CVE-2018-17456]
  11. GitHub: https://github.com/t31m0/Vulnerability-Scanner-for-Containers
    [CVE-2018-17456]
  12. GitHub: https://github.com/umahari/security
    [CVE-2018-17456]
  13. GitHub: https://github.com/zhengjim/loophole
    [CVE-2018-17456]
  14. GitHub: https://github.com/offensive-security/exploitdb-bin-sploits/blob/master/bin-sploits/45631.zip
    [EDB-45631]
  15. GitHub: https://github.com/AnonymKing/CVE-2018-17456
    [CVE-2018-17456: CVE-2018-17456漏洞复现(PoC+Exp)]
  16. GitHub: https://github.com/back2zero/GIT_CVE_2018_17456
    [CVE-2018-17456: GIT_CVE_2018_17456]

Before running any exploit against any system, make sure you are authorized by the owner of the target system(s) to perform such activity. In any other case, this would be considered as an illegal activity.

WARNING: Beware of using unverified exploits from sources such as GitHub or Exploit-DB. These exploits and PoCs could contain malware. For more information, see how to use exploits safely.

Risk Information


CVSS V2 Vector [?]: AV:N/AC:L/Au:N/C:P/I:P/A:P/E:F/RL:OF/RC:C
CVSS Base Score:7.5 (High)
Impact Subscore:6.4
Exploitability Subscore:10.0
CVSS Temporal Score:6.2 (Medium)
CVSS Environmental Score:NA (None)
Modified Impact Subscore:NA
Overall CVSS Score:6.2 (Medium)
CVSS V3 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
CVSS Base Score:9.8 (Critical)
Impact Subscore:5.9
Exploitability Subscore:3.9
CVSS Temporal Score:9.1 (Critical)
CVSS Environmental Score:NA (None)
Modified Impact Subscore:NA
Overall CVSS Score:9.1 (Critical)

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Plugin Source


This is the ubuntu_USN-3791-1.nasl nessus plugin source code. Ubuntu Security Notice (C) 2018-2020 Canonical, Inc. / NASL script (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3791-1. 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(118083);
  script_version("1.6");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/09/17");

  script_cve_id("CVE-2018-17456");
  script_xref(name:"USN", value:"3791-1");

  script_name(english:"Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS : Git vulnerability (USN-3791-1)");
  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:
"It was discovered that git did not properly validate git submodule
urls or paths. A remote attacker could possibly use this to craft a
git repository that causes arbitrary code execution when recursive
operations are used.

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/3791-1/"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected git package.");
  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:F/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:F/RL:O/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"metasploit_name", value:'Malicious Git HTTP Server For CVE-2018-17456');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:git");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:14.04");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/10/06");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/10/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/10/12");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2018-2020 Canonical, Inc. / NASL script (C) 2018-2020 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:"^(14\.04|16\.04|18\.04)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 14.04 / 16.04 / 18.04", "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:"14.04", pkgname:"git", pkgver:"1:1.9.1-1ubuntu0.9")) flag++;
if (ubuntu_check(osver:"16.04", pkgname:"git", pkgver:"1:2.7.4-0ubuntu1.5")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"git", pkgver:"1:2.17.1-1ubuntu0.3")) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    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, "git");
}

The latest version of this script can be found in these locations depending on your platform:

  • Linux / Unix:
    /opt/nessus/lib/nessus/plugins/ubuntu_USN-3791-1.nasl
  • Windows:
    C:\ProgramData\Tenable\Nessus\nessus\plugins\ubuntu_USN-3791-1.nasl
  • Mac OS X:
    /Library/Nessus/run/lib/nessus/plugins/ubuntu_USN-3791-1.nasl

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How to Run


Here is how to run the Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS : Git vulnerability (USN-3791-1) as a standalone plugin via the Nessus web user interface (https://localhost:8834/):

  1. Click to start a New Scan.
  2. Select Advanced Scan.
  3. Navigate to the Plugins tab.
  4. On the top right corner click to Disable All plugins.
  5. On the left side table select Ubuntu Local Security Checks plugin family.
  6. On the right side table select Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS : Git vulnerability (USN-3791-1) plugin ID 118083.
  7. Specify the target on the Settings tab and click to Save the scan.
  8. Run the scan.

Here are a few examples of how to run the plugin in the command line. Note that the examples below demonstrate the usage on the Linux / Unix platform.

Basic usage:

/opt/nessus/bin/nasl ubuntu_USN-3791-1.nasl -t <IP/HOST>

Run the plugin with audit trail message on the console:

/opt/nessus/bin/nasl -a ubuntu_USN-3791-1.nasl -t <IP/HOST>

Run the plugin with trace script execution written to the console (useful for debugging):

/opt/nessus/bin/nasl -T - ubuntu_USN-3791-1.nasl -t <IP/HOST>

Run the plugin with using a state file for the target and updating it (useful for running multiple plugins on the target):

/opt/nessus/bin/nasl -K /tmp/state ubuntu_USN-3791-1.nasl -t <IP/HOST>

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References


USN | Ubuntu Security Notice: See also: Similar and related Nessus plugins:
  • 117957 - Debian DSA-4311-1 : git - security update
  • 118059 - Slackware 14.0 / 14.1 / 14.2 / current : git (SSA:2018-283-01)
  • 118103 - Fedora 27 : libgit2 (2018-7d993184f6)
  • 118113 - openSUSE Security Update : git (openSUSE-2018-1147)
  • 118124 - FreeBSD : Libgit2 -- multiple vulnerabilities (8c08ab4c-d06c-11e8-b35c-001b217b3468)
  • 118169 - openSUSE Security Update : git (openSUSE-2018-1177)
  • 118213 - Amazon Linux AMI : git (ALAS-2018-1093)
  • 118244 - Fedora 27 : git (2018-d5139c4fd6)
  • 118400 - Amazon Linux 2 : git (ALAS-2018-1093)
  • 118555 - RHEL 7 : git (RHSA-2018:3408)
  • 118859 - Oracle Linux 7 : git (ELSA-2018-3408)
  • 119046 - CentOS 7 : git (CESA-2018:3408)
  • 119206 - Scientific Linux Security Update : git on SL7.x x86_64 (20181031)
  • 119516 - EulerOS 2.0 SP3 : git (EulerOS-SA-2018-1388)
  • 119546 - openSUSE Security Update : libgit2 (openSUSE-2018-1517)
  • 119649 - SUSE SLES12 Security Update : git (SUSE-SU-2018:4088-1)
  • 120129 - SUSE SLED15 / SLES15 Security Update : git (SUSE-SU-2018:3150-1)
  • 120182 - SUSE SLED15 / SLES15 Security Update : libgit2 (SUSE-SU-2018:4009-1)
  • 120213 - Fedora 29 : git (2018-06090dff59)

Version


This page has been produced using Nessus Professional 10.1.2 (#68) LINUX, Plugin set 202205072148.
Plugin file ubuntu_USN-3791-1.nasl version 1.6. For more plugins, visit the Nessus Plugin Library.

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