{"id":1717,"date":"2017-04-30T12:15:57","date_gmt":"2017-04-30T10:15:57","guid":{"rendered":"http:\/\/blogs.gentoo.org\/ago\/?p=1717"},"modified":"2017-05-01T13:35:01","modified_gmt":"2017-05-01T11:35:01","slug":"libmad-heap-based-buffer-overflow-in-mad_bit_skip-bit-c","status":"publish","type":"post","link":"https:\/\/blogs.gentoo.org\/ago\/2017\/04\/30\/libmad-heap-based-buffer-overflow-in-mad_bit_skip-bit-c\/","title":{"rendered":"libmad: heap-based buffer overflow in mad_bit_skip (bit.c)"},"content":{"rendered":"<p><strong>Description<\/strong>:<br \/>\n<a href=\"http:\/\/mad.sourceforge.net\">libmad<\/a> stays for &#8220;M&#8221;peg &#8220;A&#8221;udio &#8220;D&#8221;ecoder library.<\/p>\n<p>There is an heap overflow discovered through madplay.<\/p>\n<p>The complete ASan output:<\/p>\n<pre><font size=\"2\"># madplay -v -i -o raw:out $FILE\r\n==12603==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61200000c09f at pc 0x7f72d6aa05c0 bp 0x7fff03e32040 sp 0x7fff03e32038\r\nREAD of size 1 at 0x61200000c09f thread T0\r\n    #0 0x7f72d6aa05bf in mad_bit_skip \/tmp\/portage\/media-libs\/libmad-0.15.1b-r8\/work\/libmad-0.15.1b\/bit.c:130:21\r\n    #1 0x7f72d6b032ad in III_huffdecode \/tmp\/portage\/media-libs\/libmad-0.15.1b-r8\/work\/libmad-0.15.1b\/layer3.c:953:3\r\n    #2 0x7f72d6b032ad in III_decode \/tmp\/portage\/media-libs\/libmad-0.15.1b-r8\/work\/libmad-0.15.1b\/layer3.c:2403\r\n    #3 0x7f72d6af1a8e in mad_layer_III \/tmp\/portage\/media-libs\/libmad-0.15.1b-r8\/work\/libmad-0.15.1b\/layer3.c:2648:13\r\n    #4 0x7f72d6ab584d in mad_frame_decode \/tmp\/portage\/media-libs\/libmad-0.15.1b-r8\/work\/libmad-0.15.1b\/frame.c:453:7\r\n    #5 0x7f72d6ada4e4 in run_sync \/tmp\/portage\/media-libs\/libmad-0.15.1b-r8\/work\/libmad-0.15.1b\/decoder.c:404:11\r\n    #6 0x7f72d6ad8c59 in mad_decoder_run \/tmp\/portage\/media-libs\/libmad-0.15.1b-r8\/work\/libmad-0.15.1b\/decoder.c:557:12\r\n    #7 0x5277a1 in decode \/tmp\/portage\/media-sound\/madplay-0.15.2b-r1\/work\/madplay-0.15.2b\/player.c:1862:12\r\n    #8 0x5277a1 in play_one \/tmp\/portage\/media-sound\/madplay-0.15.2b-r1\/work\/madplay-0.15.2b\/player.c:1951\r\n    #9 0x5277a1 in play_all \/tmp\/portage\/media-sound\/madplay-0.15.2b-r1\/work\/madplay-0.15.2b\/player.c:2041\r\n    #10 0x5215a2 in player_run \/tmp\/portage\/media-sound\/madplay-0.15.2b-r1\/work\/madplay-0.15.2b\/player.c:2768:14\r\n    #11 0x50c46c in main \/tmp\/portage\/media-sound\/madplay-0.15.2b-r1\/work\/madplay-0.15.2b\/madplay.c:816:7\r\n    #12 0x7f72d599d78f in __libc_start_main \/tmp\/portage\/sys-libs\/glibc-2.23-r3\/work\/glibc-2.23\/csu\/..\/csu\/libc-start.c:289\r\n    #13 0x41aa78 in _init (\/usr\/bin\/madplay+0x41aa78)\r\n<\/font><\/pre>\n<p><strong>Affected version:<\/strong><br \/>\n0.15.1b<\/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-2017-8374<\/p>\n<p><strong>Reproducer:<\/strong><br \/>\n<a href=\"https:\/\/github.com\/asarubbo\/poc\/blob\/master\/00211-libmad-heapoverflow-mad_bit_skip\">https:\/\/github.com\/asarubbo\/poc\/blob\/master\/00211-libmad-heapoverflow-mad_bit_skip<\/a><\/p>\n<p><strong>Timeline:<\/strong><br \/>\n2017-01-01: bug discovered and reported to upstream<br \/>\n2017-04-30: blog post about the issue<br \/>\n2017-05-01: 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=\"kqtQjJgdpn\" class=\"wp-embedded-content\"><p><a href=\"http:\/\/blogs.gentoo.org\/ago\/2017\/04\/30\/libmad-heap-based-buffer-overflow-in-mad_bit_skip-bit-c\/\">libmad: heap-based buffer overflow in mad_bit_skip (bit.c)<\/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\/04\/30\/libmad-heap-based-buffer-overflow-in-mad_bit_skip-bit-c\/embed\/#?secret=kqtQjJgdpn\" data-secret=\"kqtQjJgdpn\" width=\"600\" height=\"338\" title=\"&#8220;libmad: heap-based buffer overflow in mad_bit_skip (bit.c)&#8221; &#8212; agostino&#039;s blog\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Description: libmad stays for &#8220;M&#8221;peg &#8220;A&#8221;udio &#8220;D&#8221;ecoder library. There is an heap overflow discovered through madplay. The complete ASan output: # madplay -v -i -o raw:out $FILE ==12603==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61200000c09f at pc 0x7f72d6aa05c0 bp 0x7fff03e32040 sp 0x7fff03e32038 &hellip; <a href=\"https:\/\/blogs.gentoo.org\/ago\/2017\/04\/30\/libmad-heap-based-buffer-overflow-in-mad_bit_skip-bit-c\/\">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-rH","_links":{"self":[{"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/posts\/1717"}],"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=1717"}],"version-history":[{"count":3,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/posts\/1717\/revisions"}],"predecessor-version":[{"id":1741,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/posts\/1717\/revisions\/1741"}],"wp:attachment":[{"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/media?parent=1717"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/categories?post=1717"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/tags?post=1717"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}