Snort mailing list archives

Re: Snort HTTP Inspect


From: Joel Esler <jesler () sourcefire com>
Date: Tue, 4 Jun 2013 15:19:32 -0400

Can you send the pcap so we can look at what you are seeing?

On Jun 4, 2013, at 12:22 PM, Zubair Rafique <m_zubair_rafique () yahoo com> wrote:

Hi,

I am using following configuration file to use snort in IDS mode. Unfortunately, it appears that Snort is only 
inspecting http responses and not the requests. Am, I  missing something here?

# Inline packet normalization. For more information, see README.normalize
# Does nothing in IDS mode
preprocessor normalize_ip4
preprocessor normalize_tcp: ips ecn stream
preprocessor normalize_icmp4
preprocessor normalize_ip6
preprocessor normalize_icmp6

# Target-based IP defragmentation.  For more inforation, see README.frag3
preprocessor frag3_global: max_frags 65536
preprocessor frag3_engine: policy windows detect_anomalies overlap_limit 10 min_fragment_length 100 timeout 180

# Target-Based stateful inspection/stream reassembly.  For more inforation, see README.stream5
preprocessor stream5_global: track_tcp yes, \
   track_udp yes, \
   track_icmp no, \ 
   max_tcp 262144, \
   max_udp 131072, \
   max_active_responses 2, \
   min_response_seconds 5
preprocessor stream5_tcp: policy windows, detect_anomalies, require_3whs 180, \
   overlap_limit 10, small_segments 3 bytes 150, timeout 180, \
    ports client 21 22 23 25 42 53 70 79 109 110 111 113 119 135 136 137 139 143 \
        161 445 513 514 587 593 691 1433 1521 1741 2100 3306 6070 6665 6666 6667 6668 6669 \
        7000 8181 32770 32771 32772 32773 32774 32775 32776 32777 32778 32779, \
    ports both 80 81 82 83 84 85 86 87 88 89 110 311 383 443 465 563 591 593 631 636 901 989 992 993 994 995 1220 
1414 1830 2301 2381 2809 3037 3057 3128 3702 4343 4848 5250 6080 6988 7907 7000 7001 7144 7145 7510 7802 7777 7779 \
        7801 7900 7901 7902 7903 7904 7905 7906 7908 7909 7910 7911 7912 7913 7914 7915 7916 \
        7917 7918 7919 7920 8000 8008 8014 8028 8080 8085 8088 8090 8118 8123 8180 8222 8243 8280 8300 8500 8800 8888 
8899 9000 9060 9080 9090 9091 9443 9999 10000 11371 34443 34444 41080 50002 55555
preprocessor stream5_udp: timeout 180

# performance statistics.  For more information, see the Snort Manual, Configuring Snort - Preprocessors - 
Performance Monitor
# preprocessor perfmonitor: time 300 file /var/snort/snort.stats pktcnt 10000

# HTTP normalization and anomaly detection.  For more information, see README.http_inspect
preprocessor http_inspect: global iis_unicode_map unicode.map 1252  compress_depth 65535 decompress_depth 65535 
max_gzip_mem 104857600 
preprocessor http_inspect_server: server default \
    http_methods { GET POST PUT SEARCH MKCOL COPY MOVE LOCK UNLOCK NOTIFY POLL BCOPY BDELETE BMOVE LINK UNLINK 
OPTIONS HEAD DELETE TRACE TRACK CONNECT SOURCE SUBSCRIBE UNSUBSCRIBE PROPFIND PROPPATCH BPROPFIND BPROPPATCH 
RPC_CONNECT PROXY_SUCCESS BITS_POST CCM_POST SMS_POST RPC_IN_DATA RPC_OUT_DATA RPC_ECHO_DATA } \
    chunk_length 500000 \
    server_flow_depth 300 \
    client_flow_depth 300 \
    post_depth 65495 \
    oversize_dir_length 500 \
    max_header_length 750 \
    max_headers 100 \
    max_spaces 200 \
    small_chunk_length { 10 5 } \
    ports { 80 81 82 83 84 85 86 87 88 89 311 383 591 593 631 901 1220 1414 1741 1830 2301 2381 2809 3037 3057 3128 
3702 4343 4848 5250 6080 6988 7000 7001 7144 7145 7510 7777 7779 8000 8008 8014 8028 8080 8085 8088 8090 8118 8123 
8180 8181 8222 8243 8280 8300 8500 8800 8888 8899 9000 9060 9080 9090 9091 9443 9999 10000 11371 34443 34444 41080 
50002 55555 } \
    non_rfc_char { 0x00 0x01 0x02 0x03 0x04 0x05 0x06 0x07 } \
    enable_cookie \
    extended_response_inspection \
    inspect_gzip \
    normalize_utf \
    unlimited_decompress \
    normalize_javascript \
    apache_whitespace no \
    ascii no \    
    bare_byte no \
    directory no \
    double_decode no \
    iis_backslash no \
    iis_delimiter no \
    iis_unicode no \
    multi_slash no \
    utf_8 no \
    u_encode yes \    
    webroot no



Command line: sudo /usr/local/snort/bin/snort  -i eth0 -c /usr/local/snort/etc/snort.conf -l /var/log/snort/ -A fast  
-I -L sig.pcap 


The output for HTTP is like 

===============================================================================
HTTP Inspect - encodings (Note: stream-reassembled packets included):
    POST methods:                         0         
    GET methods:                          0         
    HTTP Request Headers extracted:       0         
    HTTP Request Cookies extracted:       0         
    Post parameters extracted:            0         
    HTTP response Headers extracted:      1         
    HTTP Response Cookies extracted:      0         
    Unicode:                              0         
    Double unicode:                       0         
    Non-ASCII representable:              0         
    Directory traversals:                 0         
    Extra slashes ("//"):                 0         
    Self-referencing paths ("./"):        0         
    HTTP Response Gzip packets extracted: 0         
    Gzip Compressed Data Processed:       n/a       
    Gzip Decompressed Data Processed:     n/a       
    Total packets processed:              13        
===============================================================================


It seems like it has inspected the response successfully and can not do any thing about request. A simple rule with 
"http_method" is not firing any alert. Any ideas about it!





------------------------------------------------------------------------------
How ServiceNow helps IT people transform IT departments:
1. A cloud service to automate IT design, transition and operations
2. Dashboards that offer high-level views of enterprise services
3. A single system of record for all IT processes
http://p.sf.net/sfu/servicenow-d2d-j_______________________________________________
Snort-users mailing list
Snort-users () lists sourceforge net
Go to this URL to change user options or unsubscribe:
https://lists.sourceforge.net/lists/listinfo/snort-users
Snort-users list archive:
http://sourceforge.net/mailarchive/forum.php?forum_name=snort-users

Please visit http://blog.snort.org to stay current on all the latest Snort news!

------------------------------------------------------------------------------
How ServiceNow helps IT people transform IT departments:
1. A cloud service to automate IT design, transition and operations
2. Dashboards that offer high-level views of enterprise services
3. A single system of record for all IT processes
http://p.sf.net/sfu/servicenow-d2d-j
_______________________________________________
Snort-users mailing list
Snort-users () lists sourceforge net
Go to this URL to change user options or unsubscribe:
https://lists.sourceforge.net/lists/listinfo/snort-users
Snort-users list archive:
http://sourceforge.net/mailarchive/forum.php?forum_name=snort-users

Please visit http://blog.snort.org to stay current on all the latest Snort news!

Current thread: