confused by ranges

[Dan Langille]

On 19 Sep 2004 at 9:56, Mathieu Arnold wrote:

> +-le 18/09/2004 17:21 -0400, Dan Langille écrivait :
> | I'm having a quick look through vuln.xml:
> | 
> |         <range><ge>2.0</ge><lt>2.0.50_3</lt></range>
> | 
> | Intuitively, that means you are vulnerable if you have versions >= 
> | 2.0 or < 2.0.50_3.
> 
> This one is an AND : VER > 2.0 AND VER < 2.0.50_3

If there are two operators in a range, it is an AND.  The testing 
values always goes before the supplied operator.  Correct?

> | Is that correct?  Is that how to apply the rules. I found the DTD 
> | confused me more than the examples did.
> | 
> | This is an interesting example:
> | 
> |         <range><lt>1.1.2_1</lt></range>
> |         <range><ge>2.0</ge></range>
> | 
> | Two range statements in the same package... instead of one range with 
> | two operators.  Why?
> 
> This one is an OR, that is VER < 1.1.2_1 or VER > 2.0
> 
> because the version can't be < 1.1.2_1 and > 2.0.

If there are multiple ranges for a package within a vuln, they are 
used to construct an OR.  Actually, they could be applied separately 
to test values separately (i.e. if one was processing this one row at 
a time, you could just test the value and not worry about whether or 
not the next row contained another range entry).

Correct?

Thank you.
-- 
Dan Langille : http://www.langille.org/
BSDCan - The Technical BSD Conference - http://www.bsdcan.org/