{"id":2226,"date":"2017-09-14T12:39:24","date_gmt":"2017-09-14T10:39:24","guid":{"rendered":"http:\/\/blogs.gentoo.org\/ago\/?p=2226"},"modified":"2017-09-22T09:16:35","modified_gmt":"2017-09-22T07:16:35","slug":"bento4-stack-based-buffer-overflow-in-ap4_visualsampleentryreadfields-ap4sampleentry-cpp","status":"publish","type":"post","link":"https:\/\/blogs.gentoo.org\/ago\/2017\/09\/14\/bento4-stack-based-buffer-overflow-in-ap4_visualsampleentryreadfields-ap4sampleentry-cpp\/","title":{"rendered":"bento4: stack-based buffer overflow in AP4_VisualSampleEntry::ReadFields (Ap4SampleEntry.cpp)"},"content":{"rendered":"

Description<\/strong>:
\nbento4<\/a> is a fast, modern, open source C++ toolkit for all your MP4 and MPEG DASH media format needs.<\/p>\n

The complete ASan output of the issue:<\/p>\n

# mp42aac $FILE out.aac\r\n==9052==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7fc5ce900866 at pc 0x00000057b5a3 bp 0x7ffd0f773130 sp 0x7ffd0f773128\r\nWRITE of size 1 at 0x7fc5ce900866 thread T0\r\n    #0 0x57b5a2 in AP4_VisualSampleEntry::ReadFields(AP4_ByteStream&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4SampleEntry.cpp:780:40\r\n    #1 0x575726 in AP4_SampleEntry::Read(AP4_ByteStream&, AP4_AtomFactory&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4SampleEntry.cpp:108:5\r\n    #2 0x57d624 in AP4_VisualSampleEntry::AP4_VisualSampleEntry(unsigned int, unsigned int, AP4_ByteStream&, AP4_AtomFactory&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4SampleEntry.cpp:742:5\r\n    #3 0x57d624 in AP4_AvcSampleEntry::AP4_AvcSampleEntry(unsigned int, unsigned int, AP4_ByteStream&, AP4_AtomFactory&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4SampleEntry.cpp:994\r\n    #4 0x5cbf58 in AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream&, unsigned int, unsigned int, unsigned long long, AP4_Atom*&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4AtomFactory.cpp:305:24\r\n    #5 0x5c7fbd in AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream&, unsigned long long&, AP4_Atom*&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4AtomFactory.cpp:220:14\r\n    #6 0x586a2c in AP4_StsdAtom::AP4_StsdAtom(unsigned int, unsigned char, unsigned int, AP4_ByteStream&, AP4_AtomFactory&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4StsdAtom.cpp:100:13\r\n    #7 0x58566f in AP4_StsdAtom::Create(unsigned int, AP4_ByteStream&, AP4_AtomFactory&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4StsdAtom.cpp:56:16\r\n    #8 0x5ca71c in AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream&, unsigned int, unsigned int, unsigned long long, AP4_Atom*&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4AtomFactory.cpp:422:20\r\n    #9 0x5c7fbd in AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream&, unsigned long long&, AP4_Atom*&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4AtomFactory.cpp:220:14\r\n    #10 0x60c29f in AP4_ContainerAtom::ReadChildren(AP4_AtomFactory&, AP4_ByteStream&, unsigned long long) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4ContainerAtom.cpp:193:12\r\n    #11 0x60b1d2 in AP4_ContainerAtom::AP4_ContainerAtom(unsigned int, unsigned long long, bool, AP4_ByteStream&, AP4_AtomFactory&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4ContainerAtom.cpp:138:5\r\n    #12 0x60b1d2 in AP4_ContainerAtom::Create(unsigned int, unsigned long long, bool, bool, AP4_ByteStream&, AP4_AtomFactory&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4ContainerAtom.cpp:87\r\n    #13 0x5ca44c in AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream&, unsigned int, unsigned int, unsigned long long, AP4_Atom*&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4AtomFactory.cpp:751:20\r\n    #14 0x5c7fbd in AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream&, unsigned long long&, AP4_Atom*&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4AtomFactory.cpp:220:14\r\n    #15 0x60c561 in AP4_ContainerAtom::ReadChildren(AP4_AtomFactory&, AP4_ByteStream&, unsigned long long) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4ContainerAtom.cpp:193:12\r\n    #16 0x60b1d2 in AP4_ContainerAtom::AP4_ContainerAtom(unsigned int, unsigned long long, bool, AP4_ByteStream&, AP4_AtomFactory&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4ContainerAtom.cpp:138:5\r\n    #17 0x60b1d2 in AP4_ContainerAtom::Create(unsigned int, unsigned long long, bool, bool, AP4_ByteStream&, AP4_AtomFactory&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4ContainerAtom.cpp:87\r\n    #18 0x5ca44c in AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream&, unsigned int, unsigned int, unsigned long long, AP4_Atom*&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4AtomFactory.cpp:751:20\r\n    #19 0x5c7fbd in AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream&, unsigned long long&, AP4_Atom*&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4AtomFactory.cpp:220:14\r\n    #20 0x60c561 in AP4_ContainerAtom::ReadChildren(AP4_AtomFactory&, AP4_ByteStream&, unsigned long long) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4ContainerAtom.cpp:193:12\r\n    #21 0x60b1d2 in AP4_ContainerAtom::AP4_ContainerAtom(unsigned int, unsigned long long, bool, AP4_ByteStream&, AP4_AtomFactory&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4ContainerAtom.cpp:138:5\r\n    #22 0x60b1d2 in AP4_ContainerAtom::Create(unsigned int, unsigned long long, bool, bool, AP4_ByteStream&, AP4_AtomFactory&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4ContainerAtom.cpp:87\r\n    #23 0x5ca44c in AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream&, unsigned int, unsigned int, unsigned long long, AP4_Atom*&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4AtomFactory.cpp:751:20\r\n    #24 0x5c7fbd in AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream&, unsigned long long&, AP4_Atom*&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4AtomFactory.cpp:220:14\r\n    #25 0x60c561 in AP4_ContainerAtom::ReadChildren(AP4_AtomFactory&, AP4_ByteStream&, unsigned long long) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4ContainerAtom.cpp:193:12\r\n    #26 0x60c099 in AP4_ContainerAtom::AP4_ContainerAtom(unsigned int, unsigned long long, bool, AP4_ByteStream&, AP4_AtomFactory&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4ContainerAtom.cpp:138:5\r\n    #27 0x58e6ed in AP4_TrakAtom::AP4_TrakAtom(unsigned int, AP4_ByteStream&, AP4_AtomFactory&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4TrakAtom.cpp:165:5\r\n    #28 0x5c8e3b in AP4_TrakAtom::Create(unsigned int, AP4_ByteStream&, AP4_AtomFactory&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4TrakAtom.h:58:20\r\n    #29 0x5c8e3b in AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream&, unsigned int, unsigned int, unsigned long long, AP4_Atom*&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4AtomFactory.cpp:377\r\n    #30 0x5c7fbd in AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream&, unsigned long long&, AP4_Atom*&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4AtomFactory.cpp:220:14\r\n    #31 0x60c561 in AP4_ContainerAtom::ReadChildren(AP4_AtomFactory&, AP4_ByteStream&, unsigned long long) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4ContainerAtom.cpp:193:12\r\n    #32 0x60c099 in AP4_ContainerAtom::AP4_ContainerAtom(unsigned int, unsigned long long, bool, AP4_ByteStream&, AP4_AtomFactory&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4ContainerAtom.cpp:138:5\r\n    #33 0x5521b0 in AP4_MoovAtom::AP4_MoovAtom(unsigned int, AP4_ByteStream&, AP4_AtomFactory&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4MoovAtom.cpp:79:5\r\n    #34 0x5cad1d in AP4_MoovAtom::Create(unsigned int, AP4_ByteStream&, AP4_AtomFactory&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4MoovAtom.h:56:20\r\n    #35 0x5cad1d in AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream&, unsigned int, unsigned int, unsigned long long, AP4_Atom*&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4AtomFactory.cpp:357\r\n    #36 0x5c7fbd in AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream&, unsigned long long&, AP4_Atom*&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4AtomFactory.cpp:220:14\r\n    #37 0x5c75c0 in AP4_AtomFactory::CreateAtomFromStream(AP4_ByteStream&, AP4_Atom*&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4AtomFactory.cpp:150:12\r\n    #38 0x54ea2c in AP4_File::ParseStream(AP4_ByteStream&, AP4_AtomFactory&, bool) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4File.cpp:104:12\r\n    #39 0x54f0fa in AP4_File::AP4_File(AP4_ByteStream&, bool) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4File.cpp:78:5\r\n    #40 0x542552 in main \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Apps\/Mp42Aac\/Mp42Aac.cpp:242:32\r\n    #41 0x7fc5d1a6a680 in __libc_start_main \/var\/tmp\/portage\/sys-libs\/glibc-2.23-r4\/work\/glibc-2.23\/csu\/..\/csu\/libc-start.c:289\r\n    #42 0x44f3f8 in _start (\/usr\/bin\/mp42aac+0x44f3f8)\r\n\r\nAddress 0x7fc5ce900866 is located in stack of thread T0 at offset 102 in frame\r\n    #0 0x58676f in AP4_StsdAtom::AP4_StsdAtom(unsigned int, unsigned char, unsigned int, AP4_ByteStream&, AP4_AtomFactory&) \/tmp\/Bento4-1.5.0-617\/Source\/C++\/Core\/Ap4StsdAtom.cpp:88\r\n\r\n  This frame has 3 object(s):\r\n    [32, 36) 'entry_count'\r\n    [48, 56) 'bytes_available'\r\n    [80, 88) 'atom' 0x0ff939d18100: f1 f1 f1 f1 04 f2 00 f2 f2 f2 00 f3[f3]f3 f3 f3\r\n  0x0ff939d18110: f1 f1 f1 f1 00 00 00 00 01 f3 f3 f3 f3 f3 f3 f3\r\n  0x0ff939d18120: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\r\n  0x0ff939d18130: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\r\n  0x0ff939d18140: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\r\n  0x0ff939d18150: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\r\nShadow byte legend (one shadow byte represents 8 application bytes):\r\n  Addressable:           00\r\n  Partially addressable: 01 02 03 04 05 06 07 \r\n  Heap left redzone:       fa\r\n  Freed heap region:       fd\r\n  Stack left redzone:      f1\r\n  Stack mid redzone:       f2\r\n  Stack right redzone:     f3\r\n  Stack after return:      f5\r\n  Stack use after scope:   f8\r\n  Global redzone:          f9\r\n  Global init order:       f6\r\n  Poisoned by user:        f7\r\n  Container overflow:      fc\r\n  Array cookie:            ac\r\n  Intra object redzone:    bb\r\n  ASan internal:           fe\r\n  Left alloca redzone:     ca\r\n  Right alloca redzone:    cb\r\n==9052==ABORTING\r\n<\/font><\/pre>\n
Affected version:<\/strong>
\n1.5.0-617<\/p>\n
Fixed version:<\/strong>
\nN\/A<\/p>\n
Commit fix:<\/strong>
\nThe maintainer said that one of the previous commit fixed this issue. It needs a bisect.<\/p>\n
Credit:<\/strong>
\nThis bug was discovered by Agostino Sarubbo of Gentoo.<\/p>\n
CVE:<\/strong>
\nCVE-2017-14646<\/p>\n
Reproducer:<\/strong>
\nhttps:\/\/github.com\/asarubbo\/poc\/blob\/master\/00343-bento4-stackoverflow-AP4_VisualSampleEntry_ReadFields<\/a><\/p>\n
Timeline:<\/strong>
\n2017-09-08: bug discovered and reported to upstream
\n2017-09-14: blog post about the issue
\n2017-09-21: CVE assigned<\/p>\n
Note:<\/strong>
\nThis bug was found with American Fuzzy Lop<\/a>.
\nThis bug was identified with bare metal servers donated by Packet<\/a>. This work is also supported by the Core Infrastructure Initiative<\/a>.<\/p>\n
Permalink:<\/strong><\/p>\n
bento4: stack-based buffer overflow in AP4_VisualSampleEntry::ReadFields (Ap4SampleEntry.cpp)<\/a><\/p><\/blockquote>\n