Re: [Bug-wget] Vulnerability Report - CRLF Injection in Wget Host Part

[Tim Rühsen]

On Dienstag, 7. März 2017 02:01:06 CET Orange Tsai wrote:
> I am surprise that `http://address@hidden:address@hidden will connect to `
> evil.com`, not `good.com`.
> Most of URL parser will recognize `good.com` is host part. Like this
> advisory, https://curl.haxx.se/docs/adv_20161102J.html

The advisory is different in details (it's about # in userinfo, which is 
forbidden regarding RFC 3986).

userinfo does not contain '@' and since 
        authority   = [ userinfo "@" ] host [ ":" port ]
we know the userinfo is 'user' and than begins the host part.

What is not correct in your example is that the port is not followed by /. So 
this kind of 'garbage' should result in an error (curl and wget2 ignore 
garbage after the port, which might not be correct, but is 'relaxed' style of 
parsing).

> It seem more dangerous if a developer still rely on the result of parse URL
> than my original report.
> 
> Some testing:
> $ python try.py 'http://address@hidden:address@hidden/x'
> 
> Python scheme=http, address@hidden:address@hidden, port=
> PHP scheme=http, host=127.2.2.2, port=
> Perl scheme=http, host=127.2.2.2, port=80
> Ruby2 scheme=http, host=127.2.2.2, port=
> GO scheme=http, host=127.2.2.2, port=
> Java scheme=http, host=, port=-1
> JS scheme=http, host=127.2.2.2, port=null

The only parser that handles it correctly is Java: returning an error.

Tim

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