config/snort/snort.conf

   1 #--------------------------------------------------
   2 #   http://www.snort.org     Snort Ruleset
   3 #     Contact: snort-sigs@lists.sourceforge.net
   4 #--------------------------------------------------
   5 # $Id$
   6 #
   7 ###################################################
   8 # This file contains a sample snort configuration.
   9 # You should take the following steps to create your own custom configuration:
  10 #
  11 #  1) Set the network variables.
  12 #  2) Configure the decoder
  13 #  3) Configure the base detection engine
  14 #  4) Configure dynamic loaded libraries
  15 #  5) Configure preprocessors
  16 #  6) Configure output plugins
  17 #  7) Customize your rule set
  18 ###################################################
  19
  20 ###################################################
  21 # Step #1: Set the network variables.  For more information, see README.variables
  22 ###################################################
  23
  24 # Setup the network addresses you are protecting
  25 var HOME_NET any
  26
  27 # Set up the external network addresses.  A good start may be "any"
  28 var EXTERNAL_NET any
  29
  30 # List of DNS servers on your network
  31 var DNS_SERVERS $HOME_NET
  32
  33 # List of SMTP servers on your network
  34 var SMTP_SERVERS $HOME_NET
  35
  36 # List of web servers on your network
  37 var HTTP_SERVERS $HOME_NET
  38
  39 # List of sql servers on your network
  40 var SQL_SERVERS $HOME_NET
  41
  42 # List of telnet servers on your network
  43 var TELNET_SERVERS $HOME_NET
  44
  45 # List of ports you run web servers on
  46 portvar HTTP_PORTS  [80,2301,3128,7777,7779,8000,8008,8028,8080,8180,8888,9999]
  47
  48 # List of ports you want to look for SHELLCODE on.
  49 portvar SHELLCODE_PORTS !80
  50
  51 # List of ports you might see oracle attacks on
  52 portvar ORACLE_PORTS 1521
  53
  54 # other variables, these should not be modified
  55 var AIM_SERVERS [64.12.24.0/23,64.12.28.0/23,64.12.161.0/24,64.12.163.0/24,64.12.200.0/24,205.188.3.0/24,205.188.5.0/24,205.188.7.0/24,205.188.9.0/24,205.188.153.0/24,205.188.179.0/24,205.188.248.0/24]
  56
  57 # Path to your rules files (this can be a relative path)
  58 # Note for Windows users:  You are advised to make this an absolute path,
  59 # such as:  c:\snort\rules
  60 var RULE_PATH /etc/snort/rules
  61 var SO_RULE_PATH /etc/snort/so_rules
  62 var PREPROC_RULE_PATH /etc/snort/preproc_rules
  63
  64 ###################################################
  65 # Step #2: Configure the decoder.  For more information, see README.decode
  66 ###################################################
  67
  68 # Stop generic decode events:
  69 #config disable_decode_alerts
  70
  71 # Stop Alerts on experimental TCP options
  72 config disable_tcpopt_experimental_alerts
  73
  74 # Stop Alerts on obsolete TCP options
  75 config disable_tcpopt_obsolete_alerts
  76
  77 # Stop Alerts on T/TCP alerts
  78 #config disable_tcpopt_ttcp_alerts
  79
  80 # Stop Alerts on all other TCPOption type events:
  81 #config disable_tcpopt_alerts
  82
  83 # Stop Alerts on invalid ip options
  84 #config disable_ipopt_alerts
  85
  86 # Alert if value in length field (IP, TCP, UDP) is greater th elength of the packet
  87 # config enable_decode_oversized_alerts
  88
  89 # Same as above, but drop packet if in Inline mode (requires enable_decode_oversized_alerts)
  90 # config enable_decode_oversized_drops
  91
  92 # Configure IP / TCP checksum mode
  93 config checksum_mode: all
  94
  95 # Configure maximum number of flowbit references.  For more information, see README.flowbits
  96 # config flowbits_size: 64
  97
  98 # Configure ports to ignore
  99 # config ignore_ports: tcp 21 6667:6671 1356
 100 # config ignore_ports: udp 1:17 53
 101
 102
 103 ###################################################
 104 # Step #3: Configure the base detection engine.  For more information, see  README.decode
 105 ###################################################
 106
 107 # Configure PCRE match limitations
 108 config pcre_match_limit: 1500
 109 config pcre_match_limit_recursion: 1500
 110
 111 # Configure the detection engine  See the Snort Manual, Configuring Snort - Includes - Config
 112 config detection: search-method ac-bnfa max_queue_events 5
 113
 114 # Configure the event queue.  For more information, see README.event_queue
 115 config event_queue: max_queue 8 log 3 order_events content_length
 116
 117 # Configure Inline Resets.  See README.INLINE
 118 # config layer2resets: 00:06:76:DD:5F:E3
 119
 120
 121 ###################################################
 122 # Step #4: Configure dynamic loaded libraries.
 123 # For more information, see Snort Manual, Configuring Snort - Dynamic Modules
 124 ###################################################
 125
 126 # path to dynamic preprocessor libraries
 127 dynamicpreprocessor directory /usr/lib/snort_dynamicpreprocessor/
 128
 129 # path to base preprocessor engine
 130 dynamicengine /usr/lib/snort_dynamicengine/libsf_engine.so
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141 # path to dynamic rules libraries
 142 # dynamicdetection directory /usr/lib/snort_dynamicrules
 143
 144 ###################################################
 145 # Step #5: Configure preprocessors
 146 # For more information, see the Snort Manual, Configuring Snort - Preprocessors
 147 ###################################################
 148
 149 # Target-based IP defragmentation.  For more inforation, see README.frag3
 150 preprocessor frag3_global: max_frags 65536
 151 preprocessor frag3_engine: policy windows timeout 180
 152
 153 # Target-Based stateful inspection/stream reassembly.  For more inforation, see README.stream5
 154 preprocessor stream5_global: max_tcp 8192, track_tcp yes, track_udp no
 155 preprocessor stream5_tcp: policy windows, use_static_footprint_sizes, ports client 21 22 23 25 42 53 79 80 109 110 111 113 119 135 136 137 139 143 110 111 161 445 513 514 691 1433 1521 2100 2301 3128 3306 6665 6666 6667 6668 6669 7000 8000 8080 8180 8888 32770 32771 32772 32773 32774 32775 32776 32777 32778 32779, ports both 443 465 563 636 989 992 993 994 995 7801 7702 7900 7901 7902 7903 7904 7905 7906 6907 7908 7909 7910 7911 7912 7913 7914 7915 7916 7917 7918 7919 7920
 156 # preprocessor stream5_udp: ignore_any_rules
 157
 158 # performance statistics.  For more information, see the Snort Manual, Configuring Snort - Preprocessors - Performance Monitor
 159 # preprocessor perfmonitor: time 300 file /var/snort/snort.stats pktcnt 10000
 160
 161 # HTTP normalization and anomaly detection.  For more information, see README.http_inspect
 162 preprocessor http_inspect: global iis_unicode_map unicode.map 1252
 163
 164 preprocessor http_inspect_server: server default \
 165     apache_whitespace no \
 166     ascii no \
 167         bare_byte no \
 168         chunk_length 500000 \
 169         flow_depth 1460 \
 170         directory no \
 171         double_decode no \
 172         iis_backslash no \
 173         iis_delimiter no \
 174         iis_unicode no \
 175         multi_slash no \
 176         non_strict \
 177         oversize_dir_length 500 \
 178         ports { 80 2301 3128 7777 7779 8000 8008 8028 8080 8180 8888 9999 } \
 179         u_encode yes \
 180         non_rfc_char { 0x00 0x01 0x02 0x03 0x04 0x05 0x06 0x07 } \
 181         webroot no
 182
 183 # ONC-RPC normalization and anomaly detection.  For more information, see the Snort Manual, Configuring Snort - Preprocessors - RPC Decode
 184 preprocessor rpc_decode: 111 32770 32771 32772 32773 32774 32775 32776 32777 32778 32779 no_alert_multiple_requests no_alert_large_fragments no_alert_incomplete
 185
 186 # Back Orifice detection.
 187 preprocessor bo
 188
 189 # FTP / Telnet normalization and anomaly detection.  For more information, see README.ftptelnet
 190 preprocessor ftp_telnet: global encrypted_traffic yes check_encrypted inspection_type stateful
 191 preprocessor ftp_telnet_protocol: telnet \
 192     ayt_attack_thresh 20 \
 193     normalize ports { 23 } \
 194     detect_anomalies
 195 preprocessor ftp_telnet_protocol: ftp server default \
 196     def_max_param_len 100 \
 197     ports { 21 2100 } \
 198     ftp_cmds { USER PASS ACCT CWD SDUP SMNT QUIT REIN PORT PASV TYPE STRU MODE } \
 199     ftp_cmds { RETR STOR STOU APPE ALLO REST RNFR RNTO ABOR DELE RMD MKD PWD } \
 200     ftp_cmds { LIST NLST SITE SYST STAT HELP NOOP } \
 201     ftp_cmds { AUTH ADAT PROT PBSZ CONF ENC } \
 202     ftp_cmds { FEAT OPTS CEL CMD MACB } \
 203     ftp_cmds { MDTM REST SIZE MLST MLSD } \
 204     ftp_cmds { XPWD XCWD XCUP XMKD XRMD TEST CLNT } \
 205     alt_max_param_len 0 { CDUP QUIT REIN PASV STOU ABOR PWD SYST NOOP } \
 206     alt_max_param_len 100 { MDTM CEL XCWD SITE USER PASS REST DELE RMD SYST TEST STAT MACB EPSV CLNT LPRT } \
 207     alt_max_param_len 200 { XMKD NLST ALLO STOU APPE RETR STOR CMD RNFR HELP } \
 208     alt_max_param_len 256 { RNTO CWD } \
 209     alt_max_param_len 400 { PORT } \
 210     alt_max_param_len 512 { SIZE } \
 211     chk_str_fmt { USER PASS ACCT CWD SDUP SMNT PORT TYPE STRU MODE } \
 212     chk_str_fmt { RETR STOR STOU APPE ALLO REST RNFR RNTO DELE RMD MKD } \
 213     chk_str_fmt { LIST NLST SITE SYST STAT HELP } \
 214     chk_str_fmt { AUTH ADAT PROT PBSZ CONF ENC } \
 215     chk_str_fmt { FEAT OPTS CEL CMD } \
 216     chk_str_fmt { MDTM REST SIZE MLST MLSD } \
 217     chk_str_fmt { XPWD XCWD XCUP XMKD XRMD TEST CLNT } \
 218     cmd_validity MODE < char ASBCZ > \
 219     cmd_validity STRU < char FRP > \
 220     cmd_validity ALLO < int [ char R int ] > \
 221     cmd_validity TYPE < { char AE [ char NTC ] | char I | char L [ number ] } > \
 222     cmd_validity MDTM < [ date nnnnnnnnnnnnnn[.n[n[n]]] ] string > \
 223     cmd_validity PORT < host_port >
 224 preprocessor ftp_telnet_protocol: ftp client default \
 225     max_resp_len 256 \
 226     bounce yes \
 227     telnet_cmds no
 228
 229
 230 # SMTP normalization and anomaly detection.  For more information, see README.SMTP
 231 preprocessor smtp: ports { 25 587 691 } \
 232   inspection_type stateful \
 233   normalize cmds \
 234   normalize_cmds { EXPN VRFY RCPT } \
 235   alt_max_command_line_len 260 { MAIL } \
 236   alt_max_command_line_len 300 { RCPT } \
 237   alt_max_command_line_len 500 { HELP HELO ETRN } \
 238   alt_max_command_line_len 255 { EXPN VRFY }
 239
 240 # Portscan detection.  For more information, see README.sfportscan
 241  preprocessor sfportscan: proto  { all } memcap { 10000000 } sense_level { medium }
 242
 243 # ARP spoof detection.  For more information, see the Snort Manual - Configuring Snort - Preprocessors - ARP Spoof Preprocessor
 244 # preprocessor arpspoof
 245 # preprocessor arpspoof_detect_host: 192.168.40.1 f0:0f:00:f0:0f:00
 246
 247 # SSH anomaly detection.  For more information, see README.ssh
 248 preprocessor ssh: server_ports { 22 222 } \
 249                   max_client_bytes 19600 \
 250                   max_encrypted_packets 20 \
 251                   enable_respoverflow enable_ssh1crc32 \
 252                   enable_srvoverflow enable_protomismatch
 253
 254 # SMB / DCE-RPC normalization and anomaly detection.  For more information, see README.dcerpc2
 255 preprocessor dcerpc2: memcap 102400, events [co ]
 256 preprocessor dcerpc2_server: default, policy WinXP, \
 257     detect [smb [139,445], tcp 135, udp 135, rpc-over-http-server 593], \
 258     autodetect [tcp 1025:, udp 1025:, rpc-over-http-server 1025:], \
 259     smb_max_chain 3
 260
 261 # DNS anomaly detection.  For more information, see README.dns
 262 preprocessor dns: ports { 53 } enable_rdata_overflow
 263
 264 # SSL anomaly detection and traffic bypass.  For more information, see README.ssl
 265 preprocessor ssl: ports { 443 444 465 563 636 989 992 993 994 995 7801 7702 7900 7901 7902 7903 7904 7905 7906 6907 7908 7909 7910 7911 7912 7913 7914 7915 7916 7917 7918 7919 7920 }, trustservers, noinspect_encrypted
 266
 267
 268 ###################################################
 269 # Step #6: Configure output plugins
 270 # For more information, see Snort Manual, Configuring Snort - Output Modules
 271 ###################################################
 272
 273 # syslog
 274 # output alert_syslog: LOG_AUTH LOG_ALERT
 275
 276 # pcap
 277 # output log_tcpdump: tcpdump.log
 278
 279 # database
 280 # output database: alert, <db_type>, user=<username> password=<password> test dbname=<name> host=<hostname>
 281 # output database: log, <db_type>, user=<username> password=<password> test dbname=<name> host=<hostname>
 282
 283 # unified
 284 # output alert_unified: filename snort.alert, limit 128
 285 # output log_unified: filename snort.log, limit 128
 286
 287 # prelude
 288 # output alert_prelude
 289
 290 # metadata reference data.  do not modify these lines
 291 include /etc/snort/rules/classification.config
 292 include /etc/snort/rules/reference.config
 293
 294
 295 ###################################################
 296 # Step #7: Customize your rule set
 297 # For more information, see Snort Manual, Writing Snort Rules
 298 ###################################################
 299
 300 # site specific rules
 301
 302 # Event thresholding or suppression commands. See threshold.conf
 303 # include threshold.conf