podofo: NULL pointer dereference in PoDoFo::PdfXObject::PdfXObject (PdfXObject.cpp)

["Agostino Sarubbo" <ago () gentoo org>]

Description:
podofo is a C++ library to work with the PDF file format.

A fuzz on it discovered a null pointer dereference. The upstream project denies me to open a new ticket. So, I just 
will forward this on the -users mailing list.

The complete ASan output:

# podofocolor dummy $FILE foo
==21036==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x7fc5cfd94743 bp 0x7ffc1eaffe50 sp 
0x7ffc1eaffd40 T0)
==21036==The signal is caused by a READ memory access.
==21036==Hint: address points to the zero page.
    #0 0x7fc5cfd94742 in PoDoFo::PdfXObject::PdfXObject(PoDoFo::PdfObject*) 
/tmp/portage/app-text/podofo-0.9.5/work/podofo-0.9.5/src/doc/PdfXObject.cpp:264:74
    #1 0x529308 in ColorChanger::start() 
/tmp/portage/app-text/podofo-0.9.5/work/podofo-0.9.5/tools/podofocolor/colorchanger.cpp:137:28
    #2 0x523b8d in main /tmp/portage/app-text/podofo-0.9.5/work/podofo-0.9.5/tools/podofocolor/podofocolor.cpp:116:12
    #3 0x7fc5cd8d178f in __libc_start_main 
/tmp/portage/sys-libs/glibc-2.23-r3/work/glibc-2.23/csu/../csu/libc-start.c:289
    #4 0x4300e8 in _start (/usr/bin/podofocolor+0x4300e8)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /tmp/portage/app-text/podofo-0.9.5/work/podofo-0.9.5/src/doc/PdfXObject.cpp:264:74 in 
PoDoFo::PdfXObject::PdfXObject(PoDoFo::PdfObject*)
==21036==ABORTING

Affected version:
0.9.5

Fixed version:
N/A

Commit fix:
N/A

Credit:
This bug was discovered by Agostino Sarubbo of Gentoo.

CVE:
N/A

Reproducer:
https://github.com/asarubbo/poc/blob/master/00214-podofo-nullptr-PdfXObject-cpp

Timeline:
2017-03-01: bug discovered
2017-03-02: bug reported upstream
2017-03-02: blog post about the issue

Note:
This bug was found with American Fuzzy Lop.

Permalink:
https://blogs.gentoo.org/ago/2017/03/02/podofo-null-pointer-dereference-in-podofopdfxobjectpdfxobject-pdfxobject-cpp

--
Agostino Sarubbo
Gentoo Linux Developer