{"id":1370,"date":"2017-02-20T16:39:04","date_gmt":"2017-02-20T14:39:04","guid":{"rendered":"http:\/\/blogs.gentoo.org\/ago\/?p=1370"},"modified":"2017-03-13T11:07:27","modified_gmt":"2017-03-13T09:07:27","slug":"audiofile-heap-based-buffer-overflow-in-msadpcmdecodeblock-msadpcm-cpp","status":"publish","type":"post","link":"https:\/\/blogs.gentoo.org\/ago\/2017\/02\/20\/audiofile-heap-based-buffer-overflow-in-msadpcmdecodeblock-msadpcm-cpp\/","title":{"rendered":"audiofile: heap-based buffer overflow in MSADPCM::decodeBlock (MSADPCM.cpp)"},"content":{"rendered":"<p><strong>Description<\/strong>:<br \/>\n<a href=\"http:\/\/www.68k.org\/~michael\/audiofile\/\">audiofile<\/a> is a C-based library for reading and writing audio files in many common formats.<\/p>\n<p>A fuzz on it discovered an heap overflow.<\/p>\n<p>The complete ASan output:<\/p>\n<pre><font size=\"2\"># sfconvert @@ out.mp3 format aiff\r\n==2512==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x62d00001c45a at pc 0x7fe7476f387d bp 0x7ffc3b0e3bf0 sp 0x7ffc3b0e3be8\r\nWRITE of size 2 at 0x62d00001c45a thread T0\r\n    #0 0x7fe7476f387c in MSADPCM::decodeBlock(unsigned char const*, short*) \/tmp\/portage\/media-libs\/audiofile-0.3.6-r1\/work\/audiofile-0.3.6\/libaudiofile\/modules\/MSADPCM.cpp:222:14\r\n    #1 0x7fe7476c1ac9 in BlockCodec::runPull() \/tmp\/portage\/media-libs\/audiofile-0.3.6-r1\/work\/audiofile-0.3.6\/libaudiofile\/modules\/BlockCodec.cpp:55:3\r\n    #2 0x7fe7476fac20 in RebufferModule::runPull() \/tmp\/portage\/media-libs\/audiofile-0.3.6-r1\/work\/audiofile-0.3.6\/libaudiofile\/modules\/RebufferModule.cpp:122:3\r\n    #3 0x7fe7476ab05a in afReadFrames \/tmp\/portage\/media-libs\/audiofile-0.3.6-r1\/work\/audiofile-0.3.6\/libaudiofile\/data.cpp:222:14\r\n    #4 0x50bbeb in copyaudiodata \/tmp\/portage\/media-libs\/audiofile-0.3.6-r1\/work\/audiofile-0.3.6\/sfcommands\/sfconvert.c:340:29\r\n    #5 0x50b050 in main \/tmp\/portage\/media-libs\/audiofile-0.3.6-r1\/work\/audiofile-0.3.6\/sfcommands\/sfconvert.c:248:17\r\n    #6 0x7fe74678078f in __libc_start_main \/tmp\/portage\/sys-libs\/glibc-2.23-r3\/work\/glibc-2.23\/csu\/..\/csu\/libc-start.c:289\r\n    #7 0x419f48 in _init (\/usr\/bin\/sfconvert+0x419f48)\r\n\r\n0x62d00001c45a is located 0 bytes to the right of 32858-byte region [0x62d000014400,0x62d00001c45a)\r\nallocated by thread T0 here:\r\n    #0 0x4d2d08 in malloc \/tmp\/portage\/sys-devel\/llvm-3.9.1-r1\/work\/llvm-3.9.1.src\/projects\/compiler-rt\/lib\/asan\/asan_malloc_linux.cc:64\r\n    #1 0x7fe746419687 in operator new(unsigned long) (\/usr\/lib\/gcc\/x86_64-pc-linux-gnu\/6.3.0\/libstdc++.so.6+0xb2687)\r\n    #2 0x7fe7476af43c in afGetFrameCount \/tmp\/portage\/media-libs\/audiofile-0.3.6-r1\/work\/audiofile-0.3.6\/libaudiofile\/format.cpp:205:41\r\n    #3 0x50bb5c in copyaudiodata \/tmp\/portage\/media-libs\/audiofile-0.3.6-r1\/work\/audiofile-0.3.6\/sfcommands\/sfconvert.c:329:29\r\n    #4 0x50b050 in main \/tmp\/portage\/media-libs\/audiofile-0.3.6-r1\/work\/audiofile-0.3.6\/sfcommands\/sfconvert.c:248:17\r\n    #5 0x7fe74678078f in __libc_start_main \/tmp\/portage\/sys-libs\/glibc-2.23-r3\/work\/glibc-2.23\/csu\/..\/csu\/libc-start.c:289\r\n\r\nSUMMARY: AddressSanitizer: heap-buffer-overflow \/tmp\/portage\/media-libs\/audiofile-0.3.6-r1\/work\/audiofile-0.3.6\/libaudiofile\/modules\/MSADPCM.cpp:222:14 in MSADPCM::decodeBlock(unsigned char const*, short*)\r\nShadow bytes around the buggy address:\r\n  0x0c5a7fffb830: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\r\n  0x0c5a7fffb840: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\r\n  0x0c5a7fffb850: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\r\n  0x0c5a7fffb860: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\r\n  0x0c5a7fffb870: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\r\n=&gt;0x0c5a7fffb880: 00 00 00 00 00 00 00 00 00 00 00[02]fa fa fa fa\r\n  0x0c5a7fffb890: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa\r\n  0x0c5a7fffb8a0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa\r\n  0x0c5a7fffb8b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa\r\n  0x0c5a7fffb8c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa\r\n  0x0c5a7fffb8d0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa\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  Heap right redzone:      fb\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 partial redzone:   f4\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==2512==ABORTING\r\n<\/font><\/pre>\n<p><strong>Affected version:<\/strong><br \/>\n0.3.6<\/p>\n<p><strong>Fixed version:<\/strong><br \/>\nN\/A<\/p>\n<p><strong>Commit fix:<\/strong><br \/>\nN\/A<\/p>\n<p><strong>Credit:<\/strong><br \/>\nThis bug was discovered by Agostino Sarubbo of Gentoo.<\/p>\n<p><strong>CVE:<\/strong><br \/>\nCVE-2017-6832<\/p>\n<p><strong>Reproducer:<\/strong><br \/>\n<a href=\"https:\/\/github.com\/asarubbo\/poc\/blob\/master\/00186-audiofile-heapoverflow-MSADPCM-decodeBlock\">https:\/\/github.com\/asarubbo\/poc\/blob\/master\/00186-audiofile-heapoverflow-MSADPCM-decodeBlock<\/a>                                                                        <\/p>\n<p><strong>Timeline:<\/strong><br \/>\n2017-02-20: bug discovered and reported to upstream<br \/>\n2017-02-20: blog post about the issue<br \/>\n2017-03-12: CVE assigned<\/p>\n<p><strong>Note:<\/strong><br \/>\nThis bug was found with <a href=\"http:\/\/lcamtuf.coredump.cx\/afl\">American Fuzzy Lop<\/a>.<\/p>\n<p><strong>Permalink:<\/strong><\/p>\n<blockquote data-secret=\"Mv4Tzt0pFi\" class=\"wp-embedded-content\"><p><a href=\"http:\/\/blogs.gentoo.org\/ago\/2017\/02\/20\/audiofile-heap-based-buffer-overflow-in-msadpcmdecodeblock-msadpcm-cpp\/\">audiofile: heap-based buffer overflow in MSADPCM::decodeBlock (MSADPCM.cpp)<\/a><\/p><\/blockquote>\n<p><iframe class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; clip: rect(1px, 1px, 1px, 1px);\" src=\"http:\/\/blogs.gentoo.org\/ago\/2017\/02\/20\/audiofile-heap-based-buffer-overflow-in-msadpcmdecodeblock-msadpcm-cpp\/embed\/#?secret=Mv4Tzt0pFi\" data-secret=\"Mv4Tzt0pFi\" width=\"600\" height=\"338\" title=\"&#8220;audiofile: heap-based buffer overflow in MSADPCM::decodeBlock (MSADPCM.cpp)&#8221; &#8212; agostino&#039;s blog\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Description: audiofile is a C-based library for reading and writing audio files in many common formats. A fuzz on it discovered an heap overflow. The complete ASan output: # sfconvert @@ out.mp3 format aiff ==2512==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x62d00001c45a &hellip; <a href=\"https:\/\/blogs.gentoo.org\/ago\/2017\/02\/20\/audiofile-heap-based-buffer-overflow-in-msadpcmdecodeblock-msadpcm-cpp\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":140,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":"","jetpack_publicize_message":"","jetpack_is_tweetstorm":false,"jetpack_publicize_feature_enabled":true},"categories":[12,10],"tags":[],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p2EaBc-m6","_links":{"self":[{"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/posts\/1370"}],"collection":[{"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/users\/140"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/comments?post=1370"}],"version-history":[{"count":3,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/posts\/1370\/revisions"}],"predecessor-version":[{"id":1435,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/posts\/1370\/revisions\/1435"}],"wp:attachment":[{"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/media?parent=1370"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/categories?post=1370"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/tags?post=1370"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}