{"id":1967,"date":"2017-08-09T19:30:51","date_gmt":"2017-08-09T17:30:51","guid":{"rendered":"http:\/\/blogs.gentoo.org\/ago\/?p=1967"},"modified":"2017-08-17T22:03:14","modified_gmt":"2017-08-17T20:03:14","slug":"libfpx-double-free-in-dffromlb-docfile-cxx","status":"publish","type":"post","link":"https:\/\/blogs.gentoo.org\/ago\/2017\/08\/09\/libfpx-double-free-in-dffromlb-docfile-cxx\/","title":{"rendered":"libfpx: double-free in DfFromLB (docfile.cxx)"},"content":{"rendered":"<p><strong>Description<\/strong>:<br \/>\n<a href=\"http:\/\/www.i3a.org\/\">libfpx<\/a> is a library for manipulating FlashPIX images.<\/p>\n<p>I&#8217;m aware that the link to the upstream website does not work. I&#8217;m keeping it as well because in the future the upstream website could appear again.<br \/>\nLibfpx is not actively developed, I contacted the imagemagick project if they were available to patch security issues, but they said the they are only accepting patches and push new releases.<br \/>\nThis issue was found using the gm command line tool of graphicsmagick.<\/p>\n<p>The complete ASan output of the issue:<\/p>\n<pre><font size=\"2\"># gm identify $FILE\r\n==11267==ERROR: AddressSanitizer: attempting double-free on 0x602000001830 in thread T0:\r\n    #0 0x4cf4d0 in __interceptor_cfree \/var\/tmp\/portage\/sys-libs\/compiler-rt-sanitizers-4.0.1\/work\/compiler-rt-4.0.1.src\/lib\/asan\/asan_malloc_linux.cc:55\r\n    #1 0x7f1b6fa8bb12 in DfFromLB(ILockBytes*, unsigned short, unsigned int, unsigned short**, CExposedDocFile**, _XGUID*) \/var\/tmp\/portage\/media-libs\/libfpx-1.3.1_p6\/work\/libfpx-1.3.1-6\/oless\/docfile.cxx:76\r\n    #2 0x7f1b6fa8bdfc in DfOpenStorageOnILockBytesW(ILockBytes*, IStorage*, unsigned int, unsigned short**, unsigned int, IStorage**, _XGUID*) \/var\/tmp\/portage\/media-libs\/libfpx-1.3.1_p6\/work\/libfpx-1.3.1-6\/oless\/docfile.cxx:277\r\n    #3 0x7f1b6fa88878 in DfOpenStorageOnILockBytes(ILockBytes*, IStorage*, unsigned int, char**, unsigned int, IStorage**, _XGUID*) \/var\/tmp\/portage\/media-libs\/libfpx-1.3.1_p6\/work\/libfpx-1.3.1-6\/oless\/ascii.cxx:461\r\n    #4 0x7f1b6fa9458e in StgOpenStorageOnILockBytes \/var\/tmp\/portage\/media-libs\/libfpx-1.3.1_p6\/work\/libfpx-1.3.1-6\/oless\/storage.cxx:116\r\n    #5 0x7f1b6fa9461a in StgOpenStorage \/var\/tmp\/portage\/media-libs\/libfpx-1.3.1_p6\/work\/libfpx-1.3.1-6\/oless\/storage.cxx:70\r\n    #6 0x7f1b6fa7008e in OLEFile::OpenOLEFile(_XGUID&amp;, OLEStorage**, unsigned int) \/var\/tmp\/portage\/media-libs\/libfpx-1.3.1_p6\/work\/libfpx-1.3.1-6\/ole\/olefiles.cpp:184\r\n    #7 0x7f1b6fa70557 in OLEFile::GetCLSID(_XGUID*) \/var\/tmp\/portage\/media-libs\/libfpx-1.3.1_p6\/work\/libfpx-1.3.1-6\/ole\/olefiles.cpp:346\r\n    #8 0x7f1b6fa52d64 in PFlashPixImageView::PFlashPixImageView(FicNom&amp;, char const*, mode_Ouverture, long, PSearchHookObject*, FPXStatus*) \/var\/tmp\/portage\/media-libs\/libfpx-1.3.1_p6\/work\/libfpx-1.3.1-6\/fpx\/fpximgvw.cpp:389\r\n    #9 0x7f1b6fa55c81 in OpenImageByFilename(FicNom&amp;, char const*, unsigned long, unsigned int*, unsigned int*, unsigned int*, unsigned int*, FPXColorspace*, PFlashPixImageView**) \/var\/tmp\/portage\/media-libs\/libfpx-1.3.1_p6\/work\/libfpx-1.3.1-6\/fpx\/fpxlibio.cpp:1629\r\n    #10 0x7f1b6fa55dc9 in FPX_OpenImageByFilename \/var\/tmp\/portage\/media-libs\/libfpx-1.3.1_p6\/work\/libfpx-1.3.1-6\/fpx\/fpxlibio.cpp:1686\r\n    #11 0x7f1b6fcc45e6 in ReadFPXImage \/var\/tmp\/portage\/media-gfx\/graphicsmagick-1.3.26\/work\/GraphicsMagick-1.3.26\/coders\/fpx.c:226:16\r\n    #12 0x7f1b754f1e2b in ReadImage \/var\/tmp\/portage\/media-gfx\/graphicsmagick-1.3.26\/work\/GraphicsMagick-1.3.26\/magick\/constitute.c:1607:13\r\n    #13 0x7f1b754eee8c in PingImage \/var\/tmp\/portage\/media-gfx\/graphicsmagick-1.3.26\/work\/GraphicsMagick-1.3.26\/magick\/constitute.c:1370:9\r\n    #14 0x7f1b753baae5 in IdentifyImageCommand \/var\/tmp\/portage\/media-gfx\/graphicsmagick-1.3.26\/work\/GraphicsMagick-1.3.26\/magick\/command.c:8379:17\r\n    #15 0x7f1b753c1065 in MagickCommand \/var\/tmp\/portage\/media-gfx\/graphicsmagick-1.3.26\/work\/GraphicsMagick-1.3.26\/magick\/command.c:8869:17\r\n    #16 0x7f1b7546c7fb in GMCommandSingle \/var\/tmp\/portage\/media-gfx\/graphicsmagick-1.3.26\/work\/GraphicsMagick-1.3.26\/magick\/command.c:17396:10\r\n    #17 0x7f1b75469931 in GMCommand \/var\/tmp\/portage\/media-gfx\/graphicsmagick-1.3.26\/work\/GraphicsMagick-1.3.26\/magick\/command.c:17449:16\r\n    #18 0x7f1b73cd4680 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    #19 0x419cd8 in _init (\/usr\/bin\/gm+0x419cd8)\r\n\r\n0x602000001830 is located 0 bytes inside of 16-byte region [0x602000001830,0x602000001840)\r\nfreed by thread T0 here:\r\n    #0 0x4cf4d0 in __interceptor_cfree \/var\/tmp\/portage\/sys-libs\/compiler-rt-sanitizers-4.0.1\/work\/compiler-rt-4.0.1.src\/lib\/asan\/asan_malloc_linux.cc:55\r\n    #1 0x7f1b6fa8c001 in CDFBasis::Release() \/var\/tmp\/portage\/media-libs\/libfpx-1.3.1_p6\/work\/libfpx-1.3.1-6\/oless\/dfbasis.hxx:109\r\n    #2 0x7f1b6fa8c001 in CExposedDocFile::~CExposedDocFile() \/var\/tmp\/portage\/media-libs\/libfpx-1.3.1_p6\/work\/libfpx-1.3.1-6\/oless\/expdf.cxx:115\r\n\r\npreviously allocated by thread T0 here:\r\n    #0 0x4cf688 in malloc \/var\/tmp\/portage\/sys-libs\/compiler-rt-sanitizers-4.0.1\/work\/compiler-rt-4.0.1.src\/lib\/asan\/asan_malloc_linux.cc:66\r\n    #1 0x7f1b6f6c5337 in operator new(unsigned long) (\/usr\/lib\/gcc\/x86_64-pc-linux-gnu\/6.4.0\/libstdc++.so.6+0xb2337)\r\n\r\nSUMMARY: AddressSanitizer: double-free \/var\/tmp\/portage\/sys-libs\/compiler-rt-sanitizers-4.0.1\/work\/compiler-rt-4.0.1.src\/lib\/asan\/asan_malloc_linux.cc:55 in __interceptor_cfree\r\n==11267==ABORTING\r\n<\/font><\/pre>\n<p><strong>Affected version:<\/strong><br \/>\n1.3.1_p6<\/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-2017-12925<\/p>\n<p><strong>Reproducer:<\/strong><br \/>\n<a href=\"https:\/\/github.com\/asarubbo\/poc\/blob\/master\/00307-libfpx-doublefree-DfFromLB\">https:\/\/github.com\/asarubbo\/poc\/blob\/master\/00307-libfpx-doublefree-DfFromLB<\/a><\/p>\n<p><strong>Timeline:<\/strong><br \/>\n2017-08-01: bug discovered<br \/>\n2017-08-09: blog post about the issue<br \/>\n2017-08-17: 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>.<br \/>\nThis bug was identified with bare metal servers donated by <a href=\"https:\/\/www.packet.net\/\">Packet<\/a>. This work is also supported by the <a href=\"https:\/\/www.coreinfrastructure.org\">Core Infrastructure Initiative<\/a>.<\/p>\n<p><strong>Permalink:<\/strong><\/p>\n<blockquote data-secret=\"JNLW8DZhuz\" class=\"wp-embedded-content\"><p><a href=\"http:\/\/blogs.gentoo.org\/ago\/2017\/08\/09\/libfpx-double-free-in-dffromlb-docfile-cxx\/\">libfpx: double-free in DfFromLB (docfile.cxx)<\/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\/08\/09\/libfpx-double-free-in-dffromlb-docfile-cxx\/embed\/#?secret=JNLW8DZhuz\" data-secret=\"JNLW8DZhuz\" width=\"600\" height=\"338\" title=\"&#8220;libfpx: double-free in DfFromLB (docfile.cxx)&#8221; &#8212; agostino&#039;s blog\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Description: libfpx is a library for manipulating FlashPIX images. I&#8217;m aware that the link to the upstream website does not work. I&#8217;m keeping it as well because in the future the upstream website could appear again. Libfpx is not actively &hellip; <a href=\"https:\/\/blogs.gentoo.org\/ago\/2017\/08\/09\/libfpx-double-free-in-dffromlb-docfile-cxx\/\">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-vJ","_links":{"self":[{"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/posts\/1967"}],"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=1967"}],"version-history":[{"count":7,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/posts\/1967\/revisions"}],"predecessor-version":[{"id":2038,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/posts\/1967\/revisions\/2038"}],"wp:attachment":[{"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/media?parent=1967"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/categories?post=1967"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/tags?post=1967"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}