Re: FreeBSD and OpenBSD ftpd bug (not exploitable?)

[Patrick Lamaiziere <patfbsd () davenulle org>]

Le Fri, 05 Mar 2010 16:19:12 +0100,
Kingcope <kcope2 () googlemail com> a écrit :

> FreeBSD ftpd globbing bug - null pointer dereference ?
>
> Affected FreeBSD Releases
> +-+-+-+-+-+-+-+-+-+
> FreeBSD 8.0, 6.3 and 4.9
>
> Affected OpenBSD Releases
> +-+-+-+-+-+-+-+-+-+
> OpenBSD 4.6
>
> Could someone please shed some light into why glob doesn't fail but
> gives a zeroed out structure back?

according to glob(3) (on FreeBSD)

"gl_pathv : contains a pointer to a NULL-terminated list of
matched pathnames.  However, if gl_pathc is zero, the contents of
gl_pathv are undefined."

In your test program, glob returns 0 but with gl_pathc == 0 so it
segfaults.

ftpd should check if gl_pathc > 0.

Good catch!

Best regards.

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