Re: IPS Evasion with the Apache HTTP Server

[coderman <coderman () gmail com>]

On 6/19/07, H D Moore <fdlist () digitaloffense net> wrote:
> ...
> Many commercial IPS products fail to decode HTTP requests which use 0x0c,
> 0x0b, and 0x0d instead of the normal 0x20/0x09 separators.
> ...
> A request which contains multiple CRLF sequences instead of a valid method
> is processed by Apache, yet ignored by most IPS engines

you can use many more than that.  fill spaces with non printable and
apache (and a few others) will eat it fine.  \x01-\x1f, except ESC,
maybe CR/LF depending on placement...

is there a page somewhere that details which web servers handle sloppy
input?  (i bet the embedded httpd's are the most resistant)

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