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 include /etc/snort/vars
  25
  26 # Setup the network addresses you are protecting
  27 # taken from /etc/snort vars
  28 #var HOME_NET any
  29
  30 # Set up the external network addresses.  A good start may be "any"
  31 var EXTERNAL_NET any
  32
  33 # List of DNS servers on your network
  34 # taken from /etc/snort vars
  35 #var DNS_SERVERS $HOME_NET
  36
  37 # List of SMTP servers on your network
  38 var SMTP_SERVERS $HOME_NET
  39
  40 # List of web servers on your network
  41 var HTTP_SERVERS $HOME_NET
  42
  43 # List of sql servers on your network
  44 var SQL_SERVERS $HOME_NET
  45
  46 # List of telnet servers on your network
  47 var TELNET_SERVERS $HOME_NET
  48
  49 # List of ports you run web servers on
  50 portvar HTTP_PORTS  [80,2301,3128,7777,7779,8000,8008,8028,8080,8180,8888,9999]
  51
  52 # List of ssh ports
  53 portvar SSH_PORTS  [22,222]
  54
  55 # List of ports you want to look for SHELLCODE on.
  56 portvar SHELLCODE_PORTS !80
  57
  58 # List of ports you might see oracle attacks on
  59 portvar ORACLE_PORTS 1521
  60
  61 # other variables, these should not be modified
  62 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]
  63
  64 # Path to your rules files (this can be a relative path)
  65 # Note for Windows users:  You are advised to make this an absolute path,
  66 # such as:  c:\snort\rules
  67 var RULE_PATH /etc/snort/rules
  68 var SO_RULE_PATH /etc/snort/so_rules
  69 var PREPROC_RULE_PATH /etc/snort/preproc_rules
  70
  71
  72 ###################################################
  73 # Step #2: Configure the decoder.  For more information, see README.decode
  74 ###################################################
  75
  76 # Stop generic decode events:
  77 #config disable_decode_alerts
  78
  79 # Stop Alerts on experimental TCP options
  80 config disable_tcpopt_experimental_alerts
  81
  82 # Stop Alerts on obsolete TCP options
  83 config disable_tcpopt_obsolete_alerts
  84
  85 # Stop Alerts on T/TCP alerts
  86 #config disable_tcpopt_ttcp_alerts
  87
  88 # Stop Alerts on all other TCPOption type events:
  89 #config disable_tcpopt_alerts
  90
  91 # Stop Alerts on invalid ip options
  92 #config disable_ipopt_alerts
  93
  94 # Alert if value in length field (IP, TCP, UDP) is greater th elength of the packet
  95 # config enable_decode_oversized_alerts
  96
  97 # Same as above, but drop packet if in Inline mode (requires enable_decode_oversized_alerts)
  98 # config enable_decode_oversized_drops
  99
 100 # Configure IP / TCP checksum mode
 101 config checksum_mode: all
 102
 103 # Configure maximum number of flowbit references.  For more information, see README.flowbits
 104 # config flowbits_size: 64
 105
 106 # Configure ports to ignore
 107 # config ignore_ports: tcp 21 6667:6671 1356
 108 # config ignore_ports: udp 1:17 53
 109
 110
 111 ###################################################
 112 # Step #3: Configure the base detection engine.  For more information, see  README.decode
 113 ###################################################
 114
 115 # Configure PCRE match limitations
 116 config pcre_match_limit: 1500
 117 config pcre_match_limit_recursion: 1500
 118
 119 # Configure the detection engine  See the Snort Manual, Configuring Snort - Includes - Config
 120 config detection: search-method ac-bnfa max_queue_events 5
 121
 122 # Configure the event queue.  For more information, see README.event_queue
 123 config event_queue: max_queue 8 log 3 order_events content_length
 124
 125 # Configure Inline Resets.  See README.INLINE
 126 # config layer2resets: 00:06:76:DD:5F:E3
 127
 128
 129 ###################################################
 130 # Step #4: Configure dynamic loaded libraries.
 131 # For more information, see Snort Manual, Configuring Snort - Dynamic Modules
 132 ###################################################
 133
 134 # path to dynamic preprocessor libraries
 135 dynamicpreprocessor directory /usr/lib/snort_dynamicpreprocessor/
 136
 137 # path to base preprocessor engine
 138 dynamicengine /usr/lib/snort_dynamicengine/libsf_engine.so
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149 # path to dynamic rules libraries
 150 # dynamicdetection directory /usr/lib/snort_dynamicrules
 151
 152 ###################################################
 153 # Step #5: Configure preprocessors
 154 # For more information, see the Snort Manual, Configuring Snort - Preprocessors
 155 ###################################################
 156
 157 # Target-based IP defragmentation.  For more inforation, see README.frag3
 158 preprocessor frag3_global: max_frags 65536
 159 preprocessor frag3_engine: policy windows timeout 180
 160
 161 # Target-Based stateful inspection/stream reassembly.  For more inforation, see README.stream5
 162 preprocessor stream5_global: max_tcp 8192, track_tcp yes, track_udp no
 163 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
 164 # preprocessor stream5_udp: ignore_any_rules
 165
 166 # performance statistics.  For more information, see the Snort Manual, Configuring Snort - Preprocessors - Performance Monitor
 167 # preprocessor perfmonitor: time 300 file /var/snort/snort.stats pktcnt 10000
 168
 169 # HTTP normalization and anomaly detection.  For more information, see README.http_inspect
 170 preprocessor http_inspect: global iis_unicode_map unicode.map 1252
 171
 172 preprocessor http_inspect_server: server default \
 173     apache_whitespace no \
 174     ascii no \
 175         bare_byte no \
 176         chunk_length 500000 \
 177         flow_depth 1460 \
 178         directory no \
 179         double_decode no \
 180         iis_backslash no \
 181         iis_delimiter no \
 182         iis_unicode no \
 183         multi_slash no \
 184         non_strict \
 185         oversize_dir_length 500 \
 186         ports { 80 2301 3128 7777 7779 8000 8008 8028 8080 8180 8888 9999 } \
 187         u_encode yes \
 188         non_rfc_char { 0x00 0x01 0x02 0x03 0x04 0x05 0x06 0x07 } \
 189         webroot no
 190
 191 # ONC-RPC normalization and anomaly detection.  For more information, see the Snort Manual, Configuring Snort - Preprocessors - RPC Decode
 192 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
 193
 194 # Back Orifice detection.
 195 preprocessor bo
 196
 197 # FTP / Telnet normalization and anomaly detection.  For more information, see README.ftptelnet
 198 preprocessor ftp_telnet: global encrypted_traffic yes check_encrypted inspection_type stateful
 199 preprocessor ftp_telnet_protocol: telnet \
 200     ayt_attack_thresh 20 \
 201     normalize ports { 23 } \
 202     detect_anomalies
 203 preprocessor ftp_telnet_protocol: ftp server default \
 204     def_max_param_len 100 \
 205     ports { 21 2100 } \
 206     ftp_cmds { USER PASS ACCT CWD SDUP SMNT QUIT REIN PORT PASV TYPE STRU MODE } \
 207     ftp_cmds { RETR STOR STOU APPE ALLO REST RNFR RNTO ABOR DELE RMD MKD PWD } \
 208     ftp_cmds { LIST NLST SITE SYST STAT HELP NOOP } \
 209     ftp_cmds { AUTH ADAT PROT PBSZ CONF ENC } \
 210     ftp_cmds { FEAT OPTS CEL CMD MACB } \
 211     ftp_cmds { MDTM REST SIZE MLST MLSD } \
 212     ftp_cmds { XPWD XCWD XCUP XMKD XRMD TEST CLNT } \
 213     alt_max_param_len 0 { CDUP QUIT REIN PASV STOU ABOR PWD SYST NOOP } \
 214     alt_max_param_len 100 { MDTM CEL XCWD SITE USER PASS REST DELE RMD SYST TEST STAT MACB EPSV CLNT LPRT } \
 215     alt_max_param_len 200 { XMKD NLST ALLO STOU APPE RETR STOR CMD RNFR HELP } \
 216     alt_max_param_len 256 { RNTO CWD } \
 217     alt_max_param_len 400 { PORT } \
 218     alt_max_param_len 512 { SIZE } \
 219     chk_str_fmt { USER PASS ACCT CWD SDUP SMNT PORT TYPE STRU MODE } \
 220     chk_str_fmt { RETR STOR STOU APPE ALLO REST RNFR RNTO DELE RMD MKD } \
 221     chk_str_fmt { LIST NLST SITE SYST STAT HELP } \
 222     chk_str_fmt { AUTH ADAT PROT PBSZ CONF ENC } \
 223     chk_str_fmt { FEAT OPTS CEL CMD } \
 224     chk_str_fmt { MDTM REST SIZE MLST MLSD } \
 225     chk_str_fmt { XPWD XCWD XCUP XMKD XRMD TEST CLNT } \
 226     cmd_validity MODE < char ASBCZ > \
 227     cmd_validity STRU < char FRP > \
 228     cmd_validity ALLO < int [ char R int ] > \
 229     cmd_validity TYPE < { char AE [ char NTC ] | char I | char L [ number ] } > \
 230     cmd_validity MDTM < [ date nnnnnnnnnnnnnn[.n[n[n]]] ] string > \
 231     cmd_validity PORT < host_port >
 232 preprocessor ftp_telnet_protocol: ftp client default \
 233     max_resp_len 256 \
 234     bounce yes \
 235     telnet_cmds no
 236
 237
 238 # SMTP normalization and anomaly detection.  For more information, see README.SMTP
 239 preprocessor smtp: ports { 25 587 691 } \
 240   inspection_type stateful \
 241   normalize cmds \
 242   normalize_cmds { EXPN VRFY RCPT } \
 243   alt_max_command_line_len 260 { MAIL } \
 244   alt_max_command_line_len 300 { RCPT } \
 245   alt_max_command_line_len 500 { HELP HELO ETRN } \
 246   alt_max_command_line_len 255 { EXPN VRFY }
 247
 248 # Portscan detection.  For more information, see README.sfportscan
 249  preprocessor sfportscan: proto  { all } memcap { 10000000 } sense_level { medium }
 250
 251 # ARP spoof detection.  For more information, see the Snort Manual - Configuring Snort - Preprocessors - ARP Spoof Preprocessor
 252 # preprocessor arpspoof
 253 # preprocessor arpspoof_detect_host: 192.168.40.1 f0:0f:00:f0:0f:00
 254
 255 # SSH anomaly detection.  For more information, see README.ssh
 256 preprocessor ssh: server_ports { 22 222 } \
 257                   max_client_bytes 19600 \
 258                   max_encrypted_packets 20 \
 259                   enable_respoverflow enable_ssh1crc32 \
 260                   enable_srvoverflow enable_protomismatch
 261
 262 # SMB / DCE-RPC normalization and anomaly detection.  For more information, see README.dcerpc2
 263 preprocessor dcerpc2: memcap 102400, events [co ]
 264 preprocessor dcerpc2_server: default, policy WinXP, \
 265     detect [smb [139,445], tcp 135, udp 135, rpc-over-http-server 593], \
 266     autodetect [tcp 1025:, udp 1025:, rpc-over-http-server 1025:], \
 267     smb_max_chain 3
 268
 269 # DNS anomaly detection.  For more information, see README.dns
 270 preprocessor dns: ports { 53 } enable_rdata_overflow
 271
 272 # SSL anomaly detection and traffic bypass.  For more information, see README.ssl
 273 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
 274
 275
 276 ###################################################
 277 # Step #6: Configure output plugins
 278 # For more information, see Snort Manual, Configuring Snort - Output Modules
 279 ###################################################
 280
 281 # syslog
 282 # output alert_syslog: LOG_AUTH LOG_ALERT
 283
 284 # pcap
 285 # output log_tcpdump: tcpdump.log
 286
 287 # database
 288 # output database: alert, <db_type>, user=<username> password=<password> test dbname=<name> host=<hostname>
 289 # output database: log, <db_type>, user=<username> password=<password> test dbname=<name> host=<hostname>
 290
 291 # unified
 292 # output alert_unified: filename snort.alert, limit 128
 293 # output log_unified: filename snort.log, limit 128
 294
 295 # prelude
 296 # output alert_prelude
 297
 298 # metadata reference data.  do not modify these lines
 299 include /etc/snort/rules/classification.config
 300 include /etc/snort/rules/reference.config
 301
 302
 303 ###################################################
 304 # Step #7: Customize your rule set
 305 # For more information, see Snort Manual, Writing Snort Rules
 306 ###################################################
 307
 308 # site specific rules
 309