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 #  8) Customize preprocessor and decoder rule set
  19 #  9) Customize shared object rule set
  20 ###################################################
  21
  22 ###################################################
  23 # Step #1: Set the network variables.  For more information, see README.variables
  24 ###################################################
  25
  26 include /etc/snort/vars
  27
  28 # Setup the network addresses you are protecting
  29 # taken from /etc/snort vars
  30 #var HOME_NET any
  31
  32 # Set up the external network addresses.  A good start may be "any"
  33 var EXTERNAL_NET any
  34
  35 # List of DNS servers on your network
  36 # taken from /etc/snort vars
  37 #var DNS_SERVERS $HOME_NET
  38
  39 # List of SMTP servers on your network
  40 var SMTP_SERVERS $HOME_NET
  41
  42 # List of web servers on your network
  43 var HTTP_SERVERS $HOME_NET
  44
  45 # List of sql servers on your network
  46 var SQL_SERVERS $HOME_NET
  47
  48 # List of telnet servers on your network
  49 var TELNET_SERVERS $HOME_NET
  50
  51 # List of ssh servers on your network
  52 var SSH_SERVERS $HOME_NET
  53
  54 # List of ports you run web servers on
  55 portvar HTTP_PORTS  [80,311,591,593,901,1220,1414,1830,2301,2381,2809,3128,3702,5250,7001,7777,7779,8000,8008,8028,8080,8088,8118,8123,8180,8243,8280,8888,9090,9091,9443,9999,11371]
  56
  57 # List of ports you want to look for SHELLCODE on.
  58 portvar SHELLCODE_PORTS !80
  59
  60 # List of ports you might see oracle attacks on
  61 portvar ORACLE_PORTS 1024:
  62 # List of ssh ports
  63 portvar SSH_PORTS  [22,222]
  64 # other variables, these should not be modified
  65 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]
  66
  67 # Path to your rules files (this can be a relative path)
  68 # Note for Windows users:  You are advised to make this an absolute path,
  69 # such as:  c:\snort\rules
  70 var RULE_PATH /etc/snort/rules
  71 var SO_RULE_PATH /etc/snort/so_rules
  72 var PREPROC_RULE_PATH /etc/snort/preproc_rules
  73
  74 ###################################################
  75 # Step #2: Configure the decoder.  For more information, see README.decode
  76 ###################################################
  77
  78 # Stop generic decode events:
  79 config disable_decode_alerts
  80
  81 # Stop Alerts on experimental TCP options
  82 config disable_tcpopt_experimental_alerts
  83
  84 # Stop Alerts on obsolete TCP options
  85 config disable_tcpopt_obsolete_alerts
  86
  87 # Stop Alerts on T/TCP alerts
  88 #config disable_tcpopt_ttcp_alerts
  89
  90 # Stop Alerts on all other TCPOption type events:
  91 config disable_tcpopt_alerts
  92
  93 # Stop Alerts on invalid ip options
  94 #config disable_ipopt_alerts
  95
  96 # Alert if value in length field (IP, TCP, UDP) is greater th elength of the packet
  97 # config enable_decode_oversized_alerts
  98
  99 # Same as above, but drop packet if in Inline mode (requires enable_decode_oversized_alerts)
 100 # config enable_decode_oversized_drops
 101
 102 # Configure IP / TCP checksum mode
 103 config checksum_mode: all
 104
 105 # Configure maximum number of flowbit references.  For more information, see README.flowbits
 106 # config flowbits_size: 64
 107
 108 # Configure ports to ignore
 109 # config ignore_ports: tcp 21 6667:6671 1356
 110 # config ignore_ports: udp 1:17 53
 111
 112 # Configure active response for non inline operation. For more information, see REAMDE.active
 113 # config response: eth0 attempts 2
 114 ###################################################
 115 # Step #3: Configure the base detection engine.  For more information, see  README.decode
 116 ###################################################
 117
 118 # Configure PCRE match limitations
 119 config pcre_match_limit: 3500
 120 config pcre_match_limit_recursion: 1500
 121
 122 # Configure the detection engine  See the Snort Manual, Configuring Snort - Includes - Config
 123 config detection: search-method ac-split search-optimize max-pattern-len 20
 124
 125 # Configure the event queue.  For more information, see README.event_queue
 126 config event_queue: max_queue 8 log 3 order_events content_length
 127
 128 ###################################################
 129 # Per packet and rule latency enforcement
 130 # For more information see README.ppm
 131 ###################################################
 132
 133 # Per Packet latency configuration
 134 #config ppm: max-pkt-time 250, \
 135 #   fastpath-expensive-packets, \
 136 #   pkt-log
 137
 138 # Per Rule latency configuration
 139 #config ppm: max-rule-time 200, \
 140 #   threshold 3, \
 141 #   suspend-expensive-rules, \
 142 #   suspend-timeout 20, \
 143 #   rule-log alert
 144
 145 ###################################################
 146 # Configure Perf Profiling for debugging
 147 # For more information see README.PerfProfiling
 148 ###################################################
 149
 150 #config profile_rules: print all, sort avg_ticks
 151 #config profile_preprocs: print all, sort avg_ticks
 152 ###################################################
 153 # Step #4: Configure dynamic loaded libraries.
 154 # For more information, see Snort Manual, Configuring Snort - Dynamic Modules
 155 ###################################################
 156
 157 # path to dynamic preprocessor libraries
 158 dynamicpreprocessor directory /usr/lib/snort_dynamicpreprocessor/
 159
 160 # path to base preprocessor engine
 161 dynamicengine /usr/lib/snort_dynamicengine/libsf_engine.so
 162
 163 # path to dynamic rules libraries
 164 # dynamicdetection directory /usr/lib/snort_dynamicrules
 165
 166 ###################################################
 167 # Step #5: Configure preprocessors
 168 # For more information, see the Snort Manual, Configuring Snort - Preprocessors
 169 ###################################################
 170
 171 # Inline packet normalization. For more information, see README.normalize
 172 # Does nothing in IDS mode
 173 preprocessor normalize_ip4
 174 preprocessor normalize_tcp: ips ecn stream
 175 preprocessor normalize_icmp4
 176
 177 # Target-based IP defragmentation.  For more inforation, see README.frag3
 178 preprocessor frag3_global: max_frags 65536
 179 preprocessor frag3_engine: policy windows detect_anomalies overlap_limit 10 min_fragment_length 100 timeout 180
 180
 181 # Target-Based stateful inspection/stream reassembly.  For more inforation, see README.stream5
 182 preprocessor stream5_global: max_tcp 8192, track_tcp yes, track_udp yes, track_icmp no max_active_responses 2 min_response_seconds 5
 183
 184 preprocessor stream5_tcp: policy windows, detect_anomalies, require_3whs 180, \
 185    overlap_limit 10, small_segments 3 bytes 150, timeout 180, \
 186     ports client 21 22 23 25 42 53 79 109 110 111 113 119 135 136 137 139 143 \
 187         161 445 513 514 587 593 691 1433 1521 2100 3306 6070 6665 6666 6667 6668 6669 \
 188         7000 32770 32771 32772 32773 32774 32775 32776 32777 32778 32779, \
 189     ports both 80 311 443 465 563 591 593 636 901 989 992 993 994 995 1220 1414 1830 2301 2381 2809 3128 3702 5250 6907 7001 7702 7777 7779 \
 190         7801 7900 7901 7902 7903 7904 7905 7906 7908 7909 7910 7911 7912 7913 7914 7915 7916 \
 191         7917 7918 7919 7920 8000 8008 8028 8080 8088 8118 8123 8180 8243 8280 8888 9090 9091 9443 9999 11371
 192 preprocessor stream5_udp: timeout 180
 193
 194 # performance statistics.  For more information, see the Snort Manual, Configuring Snort - Preprocessors - Performance Monitor
 195 # preprocessor perfmonitor: time 300 file /var/snort/snort.stats pktcnt 10000
 196
 197 # HTTP normalization and anomaly detection.  For more information, see README.http_inspect
 198 preprocessor http_inspect: global iis_unicode_map unicode.map 1252 compress_depth 20480 decompress_depth 20480
 199
 200 preprocessor http_inspect_server: server default \
 201     chunk_length 500000 \
 202     server_flow_depth 0 \
 203     client_flow_depth 0 \
 204     post_depth 65495 \
 205     oversize_dir_length 500 \
 206     max_header_length 750 \
 207     max_headers 100 \
 208     ports { 80 311 591 593 901 1220 1414 1830 2301 2381 2809 3128 3702 5250 7001 7777 7779 8000 8008 8028 8080 8088 8118 8123 8180 8243 8280 8888 9090 9091 9443 9999 11371 } \
 209     non_rfc_char { 0x00 0x01 0x02 0x03 0x04 0x05 0x06 0x07 } \
 210     enable_cookie \
 211     extended_response_inspection \
 212     inspect_gzip \
 213     normalize_utf \
 214     unlimited_decompress \
 215     apache_whitespace no \
 216     ascii no \
 217     bare_byte no \
 218     base36 no \
 219     directory no \
 220     double_decode no \
 221     iis_backslash no \
 222     iis_delimiter no \
 223     iis_unicode no \
 224     multi_slash no \
 225     utf_8 no \
 226     u_encode yes \
 227     webroot no
 228
 229 # ONC-RPC normalization and anomaly detection.  For more information, see the Snort Manual, Configuring Snort - Preprocessors - RPC Decode
 230 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
 231
 232 # Back Orifice detection.
 233 preprocessor bo
 234
 235 # FTP / Telnet normalization and anomaly detection.  For more information, see README.ftptelnet
 236 preprocessor ftp_telnet: global inspection_type stateful encrypted_traffic no
 237
 238 preprocessor ftp_telnet_protocol: telnet \
 239     ayt_attack_thresh 20 \
 240     normalize ports { 23 } \
 241     detect_anomalies
 242
 243 preprocessor ftp_telnet_protocol: ftp server default \
 244     def_max_param_len 100 \
 245     ports { 21 2100 3535 } \
 246     telnet_cmds yes \
 247     ignore_telnet_erase_cmds yes \
 248     ftp_cmds { ABOR ACCT ADAT ALLO APPE AUTH CCC CDUP } \
 249     ftp_cmds { CEL CLNT CMD CONF CWD DELE ENC EPRT } \
 250     ftp_cmds { EPSV ESTA ESTP FEAT HELP LANG LIST LPRT } \
 251     ftp_cmds { LPSV MACB MAIL MDTM MIC MKD MLSD MLST } \
 252     ftp_cmds { MODE NLST NOOP OPTS PASS PASV PBSZ PORT } \
 253     ftp_cmds { PROT PWD QUIT REIN REST RETR RMD RNFR } \
 254     ftp_cmds { RNTO SDUP SITE SIZE SMNT STAT STOR STOU } \
 255     ftp_cmds { STRU SYST TEST TYPE USER XCUP XCRC XCWD } \
 256     ftp_cmds { XMAS XMD5 XMKD XPWD XRCP XRMD XRSQ XSEM } \
 257     ftp_cmds { XSEN XSHA1 XSHA256 } \
 258     alt_max_param_len 0 { ABOR CCC CDUP ESTA FEAT LPSV NOOP PASV PWD QUIT REIN STOU SYST XCUP XPWD } \
 259     alt_max_param_len 200 { ALLO APPE CMD HELP NLST RETR RNFR STOR STOU XMKD } \
 260     alt_max_param_len 256 { CWD RNTO } \
 261     alt_max_param_len 400 { PORT } \
 262     alt_max_param_len 512 { SIZE } \
 263     chk_str_fmt { ACCT ADAT ALLO APPE AUTH CEL CLNT CMD } \
 264     chk_str_fmt { CONF CWD DELE ENC EPRT EPSV ESTP HELP } \
 265     chk_str_fmt { LANG LIST LPRT MACB MAIL MDTM MIC MKD } \
 266     chk_str_fmt { MLSD MLST MODE NLST OPTS PASS PBSZ PORT } \
 267     chk_str_fmt { PROT REST RETR RMD RNFR RNTO SDUP SITE } \
 268     chk_str_fmt { SIZE SMNT STAT STOR STRU TEST TYPE USER } \
 269     chk_str_fmt { XCRC XCWD XMAS XMD5 XMKD XRCP XRMD XRSQ } \
 270     chk_str_fmt { XSEM XSEN XSHA1 XSHA256 } \
 271     cmd_validity ALLO < int [ char R int ] > \
 272     cmd_validity EPSV < [ { char 12 | char A char L char L } ] > \
 273     cmd_validity MACB < string > \
 274     cmd_validity MDTM < [ date nnnnnnnnnnnnnn[.n[n[n]]] ] string > \
 275     cmd_validity MODE < char ASBCZ > \
 276     cmd_validity PORT < host_port > \
 277     cmd_validity PROT < char CSEP > \
 278     cmd_validity STRU < char FRPO [ string ] > \
 279     cmd_validity TYPE < { char AE [ char NTC ] | char I | char L [ number ] } >
 280
 281 preprocessor ftp_telnet_protocol: ftp client default \
 282     max_resp_len 256 \
 283     bounce yes \
 284     ignore_telnet_erase_cmds yes \
 285     telnet_cmds yes
 286
 287 # SMTP normalization and anomaly detection.  For more information, see README.SMTP
 288 preprocessor smtp: ports { 25 465 587 691 } \
 289     inspection_type stateful \
 290     enable_mime_decoding \
 291     max_mime_depth 20480 \
 292     normalize cmds \
 293     normalize_cmds { ATRN AUTH BDAT CHUNKING DATA DEBUG EHLO EMAL ESAM ESND ESOM ETRN EVFY } \
 294     normalize_cmds { EXPN HELO HELP IDENT MAIL NOOP ONEX QUEU QUIT RCPT RSET SAML SEND SOML } \
 295     normalize_cmds { STARTTLS TICK TIME TURN TURNME VERB VRFY X-ADAT X-DRCP X-ERCP X-EXCH50 } \
 296     normalize_cmds { X-EXPS X-LINK2STATE XADR XAUTH XCIR XEXCH50 XGEN XLICENSE XQUE XSTA XTRN XUSR } \
 297     max_command_line_len 512 \
 298     max_header_line_len 1000 \
 299     max_response_line_len 512 \
 300     alt_max_command_line_len 260 { MAIL } \
 301     alt_max_command_line_len 300 { RCPT } \
 302     alt_max_command_line_len 500 { HELP HELO ETRN EHLO } \
 303     alt_max_command_line_len 255 { EXPN VRFY ATRN SIZE BDAT DEBUG EMAL ESAM ESND ESOM EVFY IDENT NOOP RSET } \
 304     alt_max_command_line_len 246 { SEND SAML SOML AUTH TURN ETRN DATA RSET QUIT ONEX QUEU STARTTLS TICK TIME TURNME VERB X-EXPS X-LINK2STATE XADR XAUTH XCIR XEXCH50 XGEN XLICENSE XQUE XSTA XTRN XUSR } \
 305     valid_cmds { ATRN AUTH BDAT CHUNKING DATA DEBUG EHLO EMAL ESAM ESND ESOM ETRN EVFY } \
 306     valid_cmds { EXPN HELO HELP IDENT MAIL NOOP ONEX QUEU QUIT RCPT RSET SAML SEND SOML } \
 307     valid_cmds { STARTTLS TICK TIME TURN TURNME VERB VRFY X-ADAT X-DRCP X-ERCP X-EXCH50 } \
 308     valid_cmds { X-EXPS X-LINK2STATE XADR XAUTH XCIR XEXCH50 XGEN XLICENSE XQUE XSTA XTRN XUSR } \
 309     xlink2state { enabled }
 310
 311 # Portscan detection.  For more information, see README.sfportscan
 312 preprocessor sfportscan: proto  { all } memcap { 10000000 } sense_level { medium }
 313
 314 # ARP spoof detection.  For more information, see the Snort Manual - Configuring Snort - Preprocessors - ARP Spoof Preprocessor
 315 # preprocessor arpspoof
 316 # preprocessor arpspoof_detect_host: 192.168.40.1 f0:0f:00:f0:0f:00
 317
 318 # SSH anomaly detection.  For more information, see README.ssh
 319 preprocessor ssh: server_ports { 22 222 } \
 320                   autodetect \
 321                   max_client_bytes 19600 \
 322                   max_encrypted_packets 20 \
 323                   max_server_version_len 100 \
 324                   enable_respoverflow enable_ssh1crc32 \
 325                   enable_srvoverflow enable_protomismatch
 326
 327 # SMB / DCE-RPC normalization and anomaly detection.  For more information, see README.dcerpc2
 328 preprocessor dcerpc2: memcap 102400, events [co ]
 329 preprocessor dcerpc2_server: default, policy WinXP, \
 330     detect [smb [139,445], tcp 135, udp 135, rpc-over-http-server 593], \
 331     autodetect [tcp 1025:, udp 1025:, rpc-over-http-server 1025:], \
 332     smb_max_chain 3
 333
 334 # DNS anomaly detection.  For more information, see README.dns
 335 preprocessor dns: ports { 53 } enable_rdata_overflow
 336
 337 # SSL anomaly detection and traffic bypass.  For more information, see README.ssl
 338 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
 339
 340 # SDF sensitive data preprocessor.  For more information see README.sensitive_data
 341 preprocessor sensitive_data: alert_threshold 25
 342
 343 ###################################################
 344 # Step #6: Configure output plugins
 345 # For more information, see Snort Manual, Configuring Snort - Output Modules
 346 ###################################################
 347
 348 # unified2
 349 # Recommended for most installs
 350 # output unified2: filename merged.log, limit 128, nostamp, mpls_event_types, vlan_event_types
 351
 352 # Additional configuration for specific types of installs
 353 # output alert_unified2: filename snort.alert, limit 128, nostamp
 354 # output log_unified2: filename snort.log, limit 128, nostamp
 355 # syslog
 356 # output alert_syslog: LOG_AUTH LOG_ALERT
 357
 358 # pcap
 359 # output log_tcpdump: tcpdump.log
 360
 361 # database
 362 # output database: alert, <db_type>, user=<username> password=<password> test dbname=<name> host=<hostname>
 363 # output database: log, <db_type>, user=<username> password=<password> test dbname=<name> host=<hostname>
 364
 365 # prelude
 366 # output alert_prelude
 367
 368 # metadata reference data.  do not modify these lines
 369 include /etc/snort/rules/classification.config
 370 include /etc/snort/rules/reference.config
 371
 372
 373 ###################################################
 374 # Step #7: Customize your rule set
 375 # For more information, see Snort Manual, Writing Snort Rules
 376 ###################################################
 377
 378 # site specific rules
 379