CVE request: xpdf

[Dan Rosenberg <dan.j.rosenberg () gmail com>]

I identified two issues in xpdf.  I don't think the first requires a
CVE, since it's incredibly unlikely to be exploitable, but I include
it here in case someone disagrees.

1. Due to an integer overflow when parsing CharCodes for fonts and a
failure to check the return value of a memory allocation, it is
possible to trigger writes to a narrow range of offsets from a NULL
pointer.  The chance of being able to exploit this for anything other
than a crash is very remote: on x86 32-bit, there's no chance (since
the write occurs between 0xffffffc4 and 0xfffffffc).  At least the
write lands in valid userspace on x86-64, but in my testing this
memory is never mapped.  Fixed in poppler commit at [1], hopefully
fixed soon at xpdf upstream.

2. Malformed commands may cause corruption of the internal stack used
to maintain graphics contexts, leading to potentially exploitable
memory corruption.  Fixed in poppler commit at [2], hopefully fixed
soon at xpdf upstream.

-Dan

[1] http://cgit.freedesktop.org/poppler/poppler/commit/?id=cad66a7d25abdb6aa15f3aa94a35737b119b2659
[2] http://cgit.freedesktop.org/poppler/poppler/commit/?id=8284008aa8230a92ba08d547864353d3290e9bf9