Snort mailing list archives
Re: http_inspect tuning issue
From: Joel Esler <jesler () sourcefire com>
Date: Tue, 3 Jul 2012 10:16:43 -0400
Suppress it. That's the easiest way to get rid of the alert if you find it produces no actionable information for you. On Tue, Jul 3, 2012 at 10:13 AM, Castle, Shane <scastle () bouldercounty org>wrote:
I want to tune then out because they seem to be completely useless. No info other than the bald message is ever given, no packet in which the offense occurred is captured by Snort as part of the process, and if the NSM logs are searched for the corresponding event then you see something like this: ------------------------------------------------------------------------ POST /dgw?imei=TEST&apptype=finance&src=HTC01 HTTP/1.1 User-Agent: curl/7.19.0 (i586-pc-mingw32msvc) libcurl/7.19.0 zlib/1.2.3 Content-Type: text/xml Content-Length: 335 Host: api.htc.go.yahoo.com Connection: Keep-Alive <?xml version="1.0" encoding="UTF-8"?> <request devtype="HTC_Model" deployver="HTCFinanceWidget 0.1" app="HTCFinanceWidget" appver="0.1.0" api="finance" apiver="1.0.1" acknotification="0000"> <query id="0" timestamp="0" type="getquotes"> <list><symbol>^DJI</symbol><symbol>^GSPC</symbol><symbol>^IXIC</symbol></list></query> </request> HTTP/1.1 200 OK Date: Mon, 02 Jul 2012 22:18:56 GMT X-YSTATUS: 200 Vary: Accept-Encoding Connection: close Transfer-Encoding: chunked Content-Type: text/plain;charset=UTF-8 Cache-Control: private 576 <?xml version="1.0" encoding="UTF-8"?><response><result type="getquotes" timestamp="1341267536"><list count="3" total="3"><quote><name>Dow Jones Industrial Average</name><symbol>^DJI</symbol><exchange>DJI</exchange><status>0</status><timestamp>1341259357</timestamp><price>12871.389648</price><change>-8.700195</change><changepercent>-0.067548</changepercent><open>12879.709961</open><high>12902.120117</high><low>12795.480469</low><volume>109643561</volume><marketcap>N/A</marketcap><link> http://m.yahoo.com/s/htcwf/yfinance/quote/^DJI/</link></quote><quote><name>S&P 500</name><symbol>^GSPC</symbol><exchange>SNP</exchange><status>0</status><timestamp>1341261519</timestamp><price>1365.510010</price><change>3.349976</change><changepercent>0.245931</changepercent><open>1362.329956</open><high>1366.349976</high><low>1355.699951</low><volume>544915121</volume><marketcap>N/A</marketcap><link> http://m.yahoo.com/s/htcwf/yfinance/quote/^GSPC/</link></quote><quote><name>NASDAQ Composite</name><symbol>^IXIC</symbol><exchange>Nasdaq</exchange><status>0</status><timestamp>1341263923</timestamp><price>2951.229980</price><change>16.180000</change><changepercent>0.551268</changepercent><open>2938.409912</open><high>2951.229980</high><low>2925.709961</low><volume>0</volume><marketcap>N/A</marketcap><link> http://m.yahoo.com/s/htcwf/yfinance/quote/ ^IXIC/</link></quote></list></result></response> 0 ------------------------------------------------------------------------ Here's another one: ------------------------------------------------------------------------ GET / HTTP/1.1 Accept: */* Accept-Language: en-us UA-CPU: x86 Accept-Encoding: gzip, deflate User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; GTB7.3; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; .NET4.0C; .NET4.0E) Host: my-cdhs.state.co.us Connection: Keep-Alive Cookie: GUEST_LANGUAGE_ID=en_US; COOKIE_SUPPORT=true; LOGIN="cn=greenxrj,ou=hsp,ou=bda,ou=nc,o=cty" HTTP/1.1 302 Moved Temporarily Location: https://my-cdhs.state.co.us/ Connection: close Cache-Control: no-cache Pragma: no-cache ------------------------------------------------------------------------ Now, what's the point of this alert? Even if there is actually an error in the HTTP conversation (which there does seem to be, but I can't see the issue in the second example) there is nothing harmful or malicious here. One thing I do notice: many of the servers belong to Yahoo. If I could tune out just those I think I could reduce my noise. But I still think that fundamentally 120:8 is useless and I'm going to try thresholding it so I don't see it anymore. -- Shane Castle Data Security Mgr, Boulder County IT CISSP GSEC GCIH -----Original Message----- From: waldo kitty [mailto:wkitty42 () windstream net] Sent: Monday, July 02, 2012 23:31 To: snort-users () lists sourceforge net Subject: Re: [Snort-users] http_inspect tuning issue On 7/2/2012 18:53, Castle, Shane wrote:I am getting thousands of 120:8 alerts (http_inspect: MESSAGE WITHINVALID CONTENT-LENGTH OR CHUNK SIZE) and I can't figure out how to tune http_inspect so that they aren't triggered. Any info on this would be appreciated. why would you want to tune them out? what do your pcaps (packet captures) show? this, to me, stinks of some sort of consolidated attack on your servers or possibly of trying to use them in an attack against another server or servers... i say this while looking at the thousands of attacks that my systems repel every day which are trying to use my servers against other servers... the main key factor in my case is that they are caught and automatically blocked before they can infiltrate my servers... yes, this is "slightly" against the normal flow processing of monitoring IDS/IPS alerts but it is the process that i and those i support have chosen ;) ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ 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://www.geocrawler.com/redir-sf.php3?list=snort-users Please visit http://blog.snort.org to stay current on all the latest Snort news! ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ 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://www.geocrawler.com/redir-sf.php3?list=snort-users Please visit http://blog.snort.org to stay current on all the latest Snort news!
-- Joel Esler Senior Research Engineer, VRT OpenSource Community Manager Sourcefire
------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
_______________________________________________ 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://www.geocrawler.com/redir-sf.php3?list=snort-users Please visit http://blog.snort.org to stay current on all the latest Snort news!
Current thread:
- http_inspect tuning issue Castle, Shane (Jul 02)
- Re: http_inspect tuning issue waldo kitty (Jul 02)
- Re: http_inspect tuning issue Castle, Shane (Jul 03)
- Re: http_inspect tuning issue Joel Esler (Jul 03)
- Re: http_inspect tuning issue waldo kitty (Jul 03)
- Re: http_inspect tuning issue Sunny James Fugate (Jul 03)
- Re: http_inspect tuning issue Joel Esler (Jul 04)
- Re: http_inspect tuning issue Castle, Shane (Jul 03)
- Re: http_inspect tuning issue waldo kitty (Jul 02)
- <Possible follow-ups>
- Re: http_inspect tuning issue Lay, James (Jul 03)
- Re: http_inspect tuning issue Castle, Shane (Jul 03)