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 preprocessor normalize_ip6
 177 preprocessor normalize_icmp6
 178
 179 # Target-based IP defragmentation.  For more inforation, see README.frag3
 180 preprocessor frag3_global: max_frags 65536
 181 preprocessor frag3_engine: policy windows detect_anomalies overlap_limit 10 min_fragment_length 100 timeout 180
 182
 183 # Target-Based stateful inspection/stream reassembly.  For more inforation, see README.stream5
 184 preprocessor stream5_global: max_tcp 8192, track_tcp yes, track_udp yes, track_icmp no max_active_responses 2 min_response_seconds 5
 185
 186 preprocessor stream5_tcp: policy windows, detect_anomalies, require_3whs 180, \
 187    overlap_limit 10, small_segments 3 bytes 150, timeout 180, \
 188     ports client 21 22 23 25 42 53 79 109 110 111 113 119 135 136 137 139 143 \
 189         161 445 513 514 587 593 691 1433 1521 2100 3306 6070 6665 6666 6667 6668 6669 \
 190         7000 32770 32771 32772 32773 32774 32775 32776 32777 32778 32779, \
 191     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 \
 192         7801 7900 7901 7902 7903 7904 7905 7906 7908 7909 7910 7911 7912 7913 7914 7915 7916 \
 193         7917 7918 7919 7920 8000 8008 8028 8080 8088 8118 8123 8180 8243 8280 8888 9090 9091 9443 9999 11371
 194 preprocessor stream5_udp: timeout 180
 195
 196 # performance statistics.  For more information, see the Snort Manual, Configuring Snort - Preprocessors - Performance Monitor
 197 # preprocessor perfmonitor: time 300 file /var/snort/snort.stats pktcnt 10000
 198
 199 # HTTP normalization and anomaly detection.  For more information, see README.http_inspect
 200 preprocessor http_inspect: global iis_unicode_map unicode.map 1252 compress_depth 20480 decompress_depth 20480
 201
 202 preprocessor http_inspect_server: server default \
 203     chunk_length 500000 \
 204     server_flow_depth 0 \
 205     client_flow_depth 0 \
 206     post_depth 65495 \
 207     oversize_dir_length 500 \
 208     max_header_length 750 \
 209     max_headers 100 \
 210     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 } \
 211     non_rfc_char { 0x00 0x01 0x02 0x03 0x04 0x05 0x06 0x07 } \
 212     enable_cookie \
 213     extended_response_inspection \
 214     inspect_gzip \
 215     normalize_utf \
 216     unlimited_decompress \
 217     apache_whitespace no \
 218     ascii no \
 219     bare_byte no \
 220     base36 no \
 221     directory no \
 222     double_decode no \
 223     iis_backslash no \
 224     iis_delimiter no \
 225     iis_unicode no \
 226     multi_slash no \
 227     utf_8 no \
 228     u_encode yes \
 229     webroot no
 230
 231 # ONC-RPC normalization and anomaly detection.  For more information, see the Snort Manual, Configuring Snort - Preprocessors - RPC Decode
 232 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
 233
 234 # Back Orifice detection.
 235 preprocessor bo
 236
 237 # FTP / Telnet normalization and anomaly detection.  For more information, see README.ftptelnet
 238 preprocessor ftp_telnet: global inspection_type stateful encrypted_traffic no
 239
 240 preprocessor ftp_telnet_protocol: telnet \
 241     ayt_attack_thresh 20 \
 242     normalize ports { 23 } \
 243     detect_anomalies
 244
 245 preprocessor ftp_telnet_protocol: ftp server default \
 246     def_max_param_len 100 \
 247     ports { 21 2100 3535 } \
 248     telnet_cmds yes \
 249     ignore_telnet_erase_cmds yes \
 250     ftp_cmds { ABOR ACCT ADAT ALLO APPE AUTH CCC CDUP } \
 251     ftp_cmds { CEL CLNT CMD CONF CWD DELE ENC EPRT } \
 252     ftp_cmds { EPSV ESTA ESTP FEAT HELP LANG LIST LPRT } \
 253     ftp_cmds { LPSV MACB MAIL MDTM MIC MKD MLSD MLST } \
 254     ftp_cmds { MODE NLST NOOP OPTS PASS PASV PBSZ PORT } \
 255     ftp_cmds { PROT PWD QUIT REIN REST RETR RMD RNFR } \
 256     ftp_cmds { RNTO SDUP SITE SIZE SMNT STAT STOR STOU } \
 257     ftp_cmds { STRU SYST TEST TYPE USER XCUP XCRC XCWD } \
 258     ftp_cmds { XMAS XMD5 XMKD XPWD XRCP XRMD XRSQ XSEM } \
 259     ftp_cmds { XSEN XSHA1 XSHA256 } \
 260     alt_max_param_len 0 { ABOR CCC CDUP ESTA FEAT LPSV NOOP PASV PWD QUIT REIN STOU SYST XCUP XPWD } \
 261     alt_max_param_len 200 { ALLO APPE CMD HELP NLST RETR RNFR STOR STOU XMKD } \
 262     alt_max_param_len 256 { CWD RNTO } \
 263     alt_max_param_len 400 { PORT } \
 264     alt_max_param_len 512 { SIZE } \
 265     chk_str_fmt { ACCT ADAT ALLO APPE AUTH CEL CLNT CMD } \
 266     chk_str_fmt { CONF CWD DELE ENC EPRT EPSV ESTP HELP } \
 267     chk_str_fmt { LANG LIST LPRT MACB MAIL MDTM MIC MKD } \
 268     chk_str_fmt { MLSD MLST MODE NLST OPTS PASS PBSZ PORT } \
 269     chk_str_fmt { PROT REST RETR RMD RNFR RNTO SDUP SITE } \
 270     chk_str_fmt { SIZE SMNT STAT STOR STRU TEST TYPE USER } \
 271     chk_str_fmt { XCRC XCWD XMAS XMD5 XMKD XRCP XRMD XRSQ } \
 272     chk_str_fmt { XSEM XSEN XSHA1 XSHA256 } \
 273     cmd_validity ALLO < int [ char R int ] > \
 274     cmd_validity EPSV < [ { char 12 | char A char L char L } ] > \
 275     cmd_validity MACB < string > \
 276     cmd_validity MDTM < [ date nnnnnnnnnnnnnn[.n[n[n]]] ] string > \
 277     cmd_validity MODE < char ASBCZ > \
 278     cmd_validity PORT < host_port > \
 279     cmd_validity PROT < char CSEP > \
 280     cmd_validity STRU < char FRPO [ string ] > \
 281     cmd_validity TYPE < { char AE [ char NTC ] | char I | char L [ number ] } >
 282
 283 preprocessor ftp_telnet_protocol: ftp client default \
 284     max_resp_len 256 \
 285     bounce yes \
 286     ignore_telnet_erase_cmds yes \
 287     telnet_cmds yes
 288
 289 # SMTP normalization and anomaly detection.  For more information, see README.SMTP
 290 reprocessor smtp: ports { 25 465 587 691 } \
 291     inspection_type stateful \
 292     enable_mime_decoding \
 293     max_mime_depth 20480 \
 294     normalize cmds \
 295     normalize_cmds { ATRN AUTH BDAT CHUNKING DATA DEBUG EHLO EMAL ESAM ESND ESOM ETRN EVFY } \
 296     normalize_cmds { EXPN HELO HELP IDENT MAIL NOOP ONEX QUEU QUIT RCPT RSET SAML SEND SOML } \
 297     normalize_cmds { STARTTLS TICK TIME TURN TURNME VERB VRFY X-ADAT X-DRCP X-ERCP X-EXCH50 } \
 298     normalize_cmds { X-EXPS X-LINK2STATE XADR XAUTH XCIR XEXCH50 XGEN XLICENSE XQUE XSTA XTRN XUSR } \
 299     max_command_line_len 512 \
 300     max_header_line_len 1000 \
 301     max_response_line_len 512 \
 302     alt_max_command_line_len 260 { MAIL } \
 303     alt_max_command_line_len 300 { RCPT } \
 304     alt_max_command_line_len 500 { HELP HELO ETRN EHLO } \
 305     alt_max_command_line_len 255 { EXPN VRFY ATRN SIZE BDAT DEBUG EMAL ESAM ESND ESOM EVFY IDENT NOOP RSET } \
 306     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 } \
 307     valid_cmds { ATRN AUTH BDAT CHUNKING DATA DEBUG EHLO EMAL ESAM ESND ESOM ETRN EVFY } \
 308     valid_cmds { EXPN HELO HELP IDENT MAIL NOOP ONEX QUEU QUIT RCPT RSET SAML SEND SOML } \
 309     valid_cmds { STARTTLS TICK TIME TURN TURNME VERB VRFY X-ADAT X-DRCP X-ERCP X-EXCH50 } \
 310     valid_cmds { X-EXPS X-LINK2STATE XADR XAUTH XCIR XEXCH50 XGEN XLICENSE XQUE XSTA XTRN XUSR } \
 311     xlink2state { enabled }
 312
 313 # Portscan detection.  For more information, see README.sfportscan
 314  preprocessor sfportscan: proto  { all } memcap { 10000000 } sense_level { medium }
 315
 316 # ARP spoof detection.  For more information, see the Snort Manual - Configuring Snort - Preprocessors - ARP Spoof Preprocessor
 317 # preprocessor arpspoof
 318 # preprocessor arpspoof_detect_host: 192.168.40.1 f0:0f:00:f0:0f:00
 319
 320 # SSH anomaly detection.  For more information, see README.ssh
 321 preprocessor ssh: server_ports { 22 222 } \
 322                   autodetect \
 323                   max_client_bytes 19600 \
 324                   max_encrypted_packets 20 \
 325                   max_server_version_len 100 \
 326                   enable_respoverflow enable_ssh1crc32 \
 327                   enable_srvoverflow enable_protomismatch
 328
 329 # SMB / DCE-RPC normalization and anomaly detection.  For more information, see README.dcerpc2
 330 preprocessor dcerpc2: memcap 102400, events [co ]
 331 preprocessor dcerpc2_server: default, policy WinXP, \
 332     detect [smb [139,445], tcp 135, udp 135, rpc-over-http-server 593], \
 333     autodetect [tcp 1025:, udp 1025:, rpc-over-http-server 1025:], \
 334     smb_max_chain 3
 335
 336 # DNS anomaly detection.  For more information, see README.dns
 337 preprocessor dns: ports { 53 } enable_rdata_overflow
 338
 339 # SSL anomaly detection and traffic bypass.  For more information, see README.ssl
 340 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
 341
 342 # SDF sensitive data preprocessor.  For more information see README.sensitive_data
 343 preprocessor sensitive_data: alert_threshold 25
 344
 345 ###################################################
 346 # Step #6: Configure output plugins
 347 # For more information, see Snort Manual, Configuring Snort - Output Modules
 348 ###################################################
 349
 350 # unified2
 351 # Recommended for most installs
 352 # output unified2: filename merged.log, limit 128, nostamp, mpls_event_types, vlan_event_types
 353
 354 # Additional configuration for specific types of installs
 355 # output alert_unified2: filename snort.alert, limit 128, nostamp
 356 # output log_unified2: filename snort.log, limit 128, nostamp
 357 # syslog
 358 # output alert_syslog: LOG_AUTH LOG_ALERT
 359
 360 # pcap
 361 # output log_tcpdump: tcpdump.log
 362
 363 # database
 364 # output database: alert, <db_type>, user=<username> password=<password> test dbname=<name> host=<hostname>
 365 # output database: log, <db_type>, user=<username> password=<password> test dbname=<name> host=<hostname>
 366
 367 # prelude
 368 # output alert_prelude
 369
 370 # metadata reference data.  do not modify these lines
 371 include /etc/snort/rules/classification.config
 372 include /etc/snort/rules/reference.config
 373
 374
 375 ###################################################
 376 # Step #7: Customize your rule set
 377 # For more information, see Snort Manual, Writing Snort Rules
 378 ###################################################
 379
 380 # site specific rules
 381