Snort mailing list archives

Re: Trouble with home-made rule


From: Dragos Ruiu <dr () kyx net>
Date: Sun, 17 Jun 2001 23:30:35 +0000

This is a kind of esoteric problem that is likely to bite
people who are new to C or unfamiliar with C strings.  
We ought to put a quick little check for backslashes 
and a warning message in the parser to make this 
easier to figure out in the future... I'll send you a 
patch Marty...  I've also been meaning to make 
the port #'s optional for ICMP rules too rather than 
having to put in bogus values...

cheers,
--dr

On Sunday 17 June 2001 23:14, Dragos Ruiu wrote:
Your problem is with the backslash before the quote....
\" is how you escape a quote inside the content string
so it looks like an unterminated string to the parser.

try:

"C:\\"

and remember to add another rule for lowercase:

"c:\\"

the slash in the message string may be a problem too.
I'd double it up just to make sure....

cheers,
--dr

On Monday 18 June 2001 05:51, Sheahan, Paul (PCLN-NW) wrote:
Hello,

I'm expermenting for the first time creating my own rules. I decided to
create a rule that detects whenever one of my servers responds to an
external address with "C:\" in the packet in case my servers are giving
out any info on the local drive without my knowledge. I added this rule:

alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"Outgoing c:\";
content: "c:\"; nocase;)

And received this error when starting Snort (the rule above is on line
16):

ERROR Line 16 => Content data needs to be enclosed in quotation marks
(")!

Obviously the closed quotation is there. I thought maybe the ":" in "C:\"
is confusing Snort? Just a guess. Anyone know how I can fix this?

Thanks!


_______________________________________________
Snort-users mailing list
Snort-users () lists sourceforge net
Go to this URL to change user options or unsubscribe:
http://lists.sourceforge.net/lists/listinfo/snort-users
Snort-users list archive:
http://www.geocrawler.com/redir-sf.php3?list=snort-users

_______________________________________________
Snort-users mailing list
Snort-users () lists sourceforge net
Go to this URL to change user options or unsubscribe:
http://lists.sourceforge.net/lists/listinfo/snort-users
Snort-users list archive:
http://www.geocrawler.com/redir-sf.php3?list=snort-users

_______________________________________________
Snort-users mailing list
Snort-users () lists sourceforge net
Go to this URL to change user options or unsubscribe:
http://lists.sourceforge.net/lists/listinfo/snort-users
Snort-users list archive:
http://www.geocrawler.com/redir-sf.php3?list=snort-users


Current thread: