Re: CVE-2015-0848 - Heap overflow on libwmf0.2-7

[Fernando Muñoz <fernando () null-life com>]

Stefan,

There are two additionals invalid read issues inside libwmf, I
submitted both to Debian a while ago, I don't know if they are worth
to fix on a security update. One of them has a patch by me (not
heavily tested though)

invalid read on meta_pen_create player/meta.h (+ patch)
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=784205

wmf2gd/wmf2eps invalid read
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=784192

Thanks.


On Wed, Jun 3, 2015 at 6:10 AM, Stefan Cornelius <scorneli () redhat com> wrote:
> On Mon, 1 Jun 2015 03:06:57 -0500
> Fernando Muñoz <fernando () null-life com> wrote:
>
> > libwmf is affected by a heap overflow on the function that decodes
> > BMP images.
> >
> > WMF files may contain both vector graphics and bitmap components. With
> > the attached WMF file, the issue can be reproduced, an overflow
> > happens because image_size gets a value of 32, that space is used to
> > allocate data->image
>
> There's another issue related to the RLE decoding. DecodeImage() does
> not check that the run-length "count" fits into the total size of the
> image, which can lead to a heap-based buffer overflow. I've not
> assigned a CVE ID to this (mainly because I'm not sure if this
> warrants a new CVE or should be bundled with CVE-2015-0848, so I leave
> that up to the CVE experts on the list).
>
> We have some possible fixes in our bug [1], but be cautious - these are
> not fully vetted yet. So far, however, they look fine to me.
>
> [1] https://bugzilla.redhat.com/show_bug.cgi?id=1227243
> --
> Stefan Cornelius / Red Hat Product Security
>
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