Re: Serious problems Snort 2.9 with relative content matches using http_inspect preprocessor and http_uri keyword

[rmkml <rmkml () yahoo fr>]

Hi L0rd,

Yes it's fire with snort v2.9.5.3 :

cd snort-2.9.5.3/src # same snort.conf than v2.9.5.6...

./snort ... :

11/07-11:49:40.590605  [**] [1:11:1] Dont Cry 4 Me Trojanina [**] [Priority: 0] {TCP} 192.168.42.150:53853 -> 
173.194.40.178:80
11/07-11:49:40.590605  [**] [1:10:1] Dont Cry 4 Me Trojanina [**] [Priority: 0] {TCP} 192.168.42.150:53853 -> 
173.194.40.178:80

Could you share your snort.conf + pcap + snort cmd line please ?

Regards
@Rmkml


On Wed, 20 Nov 2013, L0rd Ch0de1m0rt wrote:

> Hello,
>
> Thanks rmkml and all whom responded.
>
> As stated, the latests version I tested on was SNORT 2.9.5.3.  This is a fairly recent version IIRC (I do have many 
> devices that are and have to run older versions -- some 2.8.x and upgrading is not an
> option at this point)  ...... can someone from Sourcefire tell me if version v2.9.5.3 is still supported?  Can Joel or 
> Cisco company say to me that they are seeing this issue and if/when i was fixed? Can
> you known which versions are affected? I was hoping this problem would go away but upper mgmt is breathing on my neck 
> about this.
>
> Thanks!
>
> Cheers,
>
> Lord C.
>
>
> On Thu, Nov 7, 2013 at 4:42 PM, L0rd Ch0de1m0rt <l0rdch0de1m0rt () gmail com> wrote:
>       Hello.
>
> @Bad Horse: I tried http_raw_uri and it still does not work.  That is good point about the colon in the uri.  The funny 
> thing is that if I increase the distance, it WILL work so it seems that maybe
> the parser it getting "stuck" on the first content match (0x2F) and not evaluating everything in full.  To test, I 
> tried this rule and it DID work! :
>
> alert tcp $HOME_NET any -> $EXTERNAL_NET $HTTP_PORTS (msg:"Dont Cry 4 Me Trojanina"; flow:established, to_server; content:"GET"; 
> http_method; content:"|2F|"; http_uri; content:"|3A|"; http_uri;
> distance:1; within:50;)
>
> @Baggy: I tried a number of versions and the latest was 2.9.5.3 I believe, is that still supported?
>
> Thanks for everyones' help.
>
> Cheers,
>
> Lord C.
>
>
> On Thu, Nov 7, 2013 at 12:31 PM, Bhagya Bantwal <bbantwal () sourcefire com> wrote:
>       Hello,
>
> Have you tested with snort version snort 2.9.5.5? With this snort version I see the alert as expected.
>
> If it still doesn't work, you can send me your pcap & conf and I will take a look.
>
> Thanks!
> B
>
>
> On Wed, Nov 6, 2013 at 2:01 PM, L0rd Ch0de1m0rt <l0rdch0de1m0rt () gmail com> wrote:
>       Hello,
>
>       Previously I posted on this list with an email subject of, "distance, within, and negated matches".  Today I 
> bring another issue that I am having that I believes could be related and
>       is non-trivial and super serious.
>
>       When I analyze it I believe that relative (1 byte?) content matches are not being properly applied in the 
> http_uri buffer.  Other buffers for the http preprocessor may be affected as
>       well but I have not tested them but I won't be suprised if they are also infected by this bug.
>
>       This is an example of the rule Im using:
>        
>       alert tcp $HOME_NET any -> $EXTERNAL_NET $HTTP_PORTS (msg:"Dont Cry 4 Me Trojanina"; flow:established, to_server; 
> content:"GET"; http_method; content:"|2F|"; http_uri;
>       content:"|3A|"; http_uri; distance:1; within:20;)
>
>       Using a simple pcap ("Follow TCP stream" output from Ethereal is here:)
>
>       GET /iused/2/trust/the.http_preprocessor/sad1/cr1090hs:SN-IF-FF- HTTP/1.1
>
>       The rule does not alert even though the Snort output shows that the HTTP data is being properly recognized and 
> processed by the http_inspect preprocessor. The Snort output shows that
>       the specific GET request is being recognized as a HTTP "GET" request.
>
>       When I remove the http_inspect directives, the rule starts to work, this is an example:
>
>       alert tcp $HOME_NET any -> $EXTERNAL_NET $HTTP_PORTS (msg:"Dont Cry 4 Me Trojanina"; flow:established, to_server; content:"GET"; 
> http_method; content:"|2F|"; content:"|3A|";
>       distance:1; within:20;)
>
>       Is this (still?) a known issue?  I have tested this on multiple different versions of Snort 2.9.
>
>       Cheers,
>
>       Lord C.
>
> ------------------------------------------------------------------------------
> November Webinars for C, C++, Fortran Developers
> Accelerate application performance with scalable programming models. Explore
> techniques for threading, error checking, porting, and tuning. Get the most
> from the latest Intel processors and coprocessors. See abstracts and register
> http://pubads.g.doubleclick.net/gampad/clk?id=60136231&iu=/4140/ostg.clktrk
> _______________________________________________
> Snort-devel mailing list
> Snort-devel () lists sourceforge net
> https://lists.sourceforge.net/lists/listinfo/snort-devel
> Archive:
> http://sourceforge.net/mailarchive/forum.php?forum_name=snort-devel
>
> Please visit http://blog.snort.org for the latest news about Snort!
------------------------------------------------------------------------------
Shape the Mobile Experience: Free Subscription
Software experts and developers: Be at the forefront of tech innovation.
Intel(R) Software Adrenaline delivers strategic insight and game-changing 
conversations that shape the rapidly evolving mobile landscape. Sign up now. 
http://pubads.g.doubleclick.net/gampad/clk?id=63431311&iu=/4140/ostg.clktrk

_______________________________________________
Snort-devel mailing list
Snort-devel () lists sourceforge net
https://lists.sourceforge.net/lists/listinfo/snort-devel
Archive:
http://sourceforge.net/mailarchive/forum.php?forum_name=snort-devel

Please visit http://blog.snort.org for the latest news about Snort!