[SECURITY] [DLA 1177-1] poppler security update

Package : poppler
Version : 0.18.4-6+deb7u4
CVE ID : CVE-2017-14975 CVE-2017-14976 CVE-2017-14977
CVE-2017-15565
Debian Bug : 879066 877952 877954 877957

It was discovered that poppler, a PDF rendering library, was affected
by several denial-of-service (application crash), null pointer
dereferences and heap-based buffer over-read bugs:

CVE-2017-14975
The FoFiType1C::convertToType0 function in FoFiType1C.cc
has a NULL pointer dereference vulnerability because a data structure
is not initialized, which allows an attacker to launch a denial of
service attack.

CVE-2017-14976
The FoFiType1C::convertToType0 function in FoFiType1C.cc
has a heap-based buffer over-read vulnerability if an out-of-bounds
font dictionary index is encountered, which allows an attacker to
launch a denial of service attack.

CVE-2017-14977
The FoFiTrueType::getCFFBlock function in FoFiTrueType.cc
has a NULL pointer dereference vulnerability due to lack of validation
of a table pointer, which allows an attacker to launch a denial of
service attack.

CVE-2017-15565
NULL Pointer Dereference exists in the GfxImageColorMap::getGrayLine()
function in GfxState.cc via a crafted PDF document.

For Debian 7 "Wheezy", these problems have been fixed in version
0.18.4-6+deb7u4.

We recommend that you upgrade your poppler packages.

Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://wiki.debian.org/LTS