{"id":610,"date":"2016-09-22T17:33:49","date_gmt":"2016-09-22T15:33:49","guid":{"rendered":"http:\/\/blogs.gentoo.org\/ago\/?p=610"},"modified":"2016-12-01T15:51:18","modified_gmt":"2016-12-01T13:51:18","slug":"mupdf-use-after-free-in-pdf_to_num-pdf-object-c","status":"publish","type":"post","link":"https:\/\/blogs.gentoo.org\/ago\/2016\/09\/22\/mupdf-use-after-free-in-pdf_to_num-pdf-object-c\/","title":{"rendered":"mupdf: use-after-free in pdf_to_num (pdf-object.c)"},"content":{"rendered":"<p><strong>Description<\/strong>:<br \/>\n<a href=\"http:\/\/mupdf.com\/\">mupdf<\/a> is a lightweight PDF viewer and toolkit written in portable C.<\/p>\n<p>A fuzzing through mutool revealed a use-after-free.<\/p>\n<p>The complete ASan output:<\/p>\n<pre><font size=\"2\"># mutool info $FILE\r\n==5430==ERROR: AddressSanitizer: heap-use-after-free on address 0x60300000ea42 at pc 0x7fbc4c3824e5 bp 0x7ffee68ead70 sp 0x7ffee68ead68                                                                                                                                       \r\nREAD of size 1 at 0x60300000ea42 thread T0                                                                                                                                                                                                                                    \r\n    #0 0x7fbc4c3824e4 in pdf_to_num \/var\/tmp\/portage\/app-text\/mupdf-1.9a\/work\/mupdf-1.9a\/source\/pdf\/pdf-object.c:375:35                                                                                                                                                       \r\n    #1 0x53f042 in gatherfonts \/var\/tmp\/portage\/app-text\/mupdf-1.9a\/work\/mupdf-1.9a\/source\/tools\/pdfinfo.c:259:46                                                                                                                                                             \r\n    #2 0x53f042 in gatherresourceinfo \/var\/tmp\/portage\/app-text\/mupdf-1.9a\/work\/mupdf-1.9a\/source\/tools\/pdfinfo.c:595                                                                                                                                                         \r\n    #3 0x53913a in gatherpageinfo \/var\/tmp\/portage\/app-text\/mupdf-1.9a\/work\/mupdf-1.9a\/source\/tools\/pdfinfo.c:661:2                                                                                                                                                           \r\n    #4 0x53913a in showinfo \/var\/tmp\/portage\/app-text\/mupdf-1.9a\/work\/mupdf-1.9a\/source\/tools\/pdfinfo.c:957                                                                                                                                                                   \r\n    #5 0x537d46 in pdfinfo_info \/var\/tmp\/portage\/app-text\/mupdf-1.9a\/work\/mupdf-1.9a\/source\/tools\/pdfinfo.c:1029:3                                                                                                                                                            \r\n    #6 0x537d46 in pdfinfo_main \/var\/tmp\/portage\/app-text\/mupdf-1.9a\/work\/mupdf-1.9a\/source\/tools\/pdfinfo.c:1077                                                                                                                                                              \r\n    #7 0x4f8ace in main \/var\/tmp\/portage\/app-text\/mupdf-1.9a\/work\/mupdf-1.9a\/source\/tools\/mutool.c:104:12                                                                                                                                                                     \r\n    #8 0x7fbc4ae1f61f in __libc_start_main \/var\/tmp\/portage\/sys-libs\/glibc-2.22-r4\/work\/glibc-2.22\/csu\/libc-start.c:289                                                                                                                                                       \r\n    #9 0x41f9c8 in _init (\/usr\/bin\/mutool+0x41f9c8)                                                                                                                                                                                                                           \r\n                                                                                                                                                                                                                                                                              \r\n0x60300000ea42 is located 2 bytes inside of 24-byte region [0x60300000ea40,0x60300000ea58)                                                                                                                                                                                    \r\nfreed by thread T0 here:                                                                                                                                                                                                                                                      \r\n    #0 0x4c6c10 in free \/var\/tmp\/portage\/sys-devel\/llvm-3.8.0-r3\/work\/llvm-3.8.0.src\/projects\/compiler-rt\/lib\/asan\/asan_malloc_linux.cc:38                                                                                                                                    \r\n    #1 0x7fbc4bf33830 in fz_free \/var\/tmp\/portage\/app-text\/mupdf-1.9a\/work\/mupdf-1.9a\/source\/fitz\/memory.c:187:2                                                                                                                                                              \r\n                                                                                                                                                                                                                                                                              \r\npreviously allocated by thread T0 here:                                                                                                                                                                                                                                       \r\n    #0 0x4c6f18 in malloc \/var\/tmp\/portage\/sys-devel\/llvm-3.8.0-r3\/work\/llvm-3.8.0.src\/projects\/compiler-rt\/lib\/asan\/asan_malloc_linux.cc:52                                                                                                                                  \r\n    #1 0x7fbc4bf2a86f in do_scavenging_malloc \/var\/tmp\/portage\/app-text\/mupdf-1.9a\/work\/mupdf-1.9a\/source\/fitz\/memory.c:17:7                                                                                                                                                  \r\n    #2 0x7fbc4bf2a86f in fz_malloc \/var\/tmp\/portage\/app-text\/mupdf-1.9a\/work\/mupdf-1.9a\/source\/fitz\/memory.c:57                                                                                                                                                               \r\n    #3 0x7fbc4c37f94d in pdf_new_indirect \/var\/tmp\/portage\/app-text\/mupdf-1.9a\/work\/mupdf-1.9a\/source\/pdf\/pdf-object.c:186:8                                                                                                                                                  \r\n                                                                                                                                                                                                                                                                              \r\nSUMMARY: AddressSanitizer: heap-use-after-free \/var\/tmp\/portage\/app-text\/mupdf-1.9a\/work\/mupdf-1.9a\/source\/pdf\/pdf-object.c:375:35 in pdf_to_num                                                                                                                              \r\nShadow bytes around the buggy address:                                                                                                                                                                                                                                        \r\n  0x0c067fff9cf0: fd fd fa fa fd fd fd fa fa fa fd fd fd fa fa fa                                                                                                                                                                                                             \r\n  0x0c067fff9d00: fd fd fd fd fa fa fd fd fd fa fa fa fd fd fd fa                                                                                                                                                                                                             \r\n  0x0c067fff9d10: fa fa fd fd fd fd fa fa fd fd fd fa fa fa fd fd                                                                                                                                                                                                             \r\n  0x0c067fff9d20: fd fa fa fa fd fd fd fd fa fa fd fd fd fa fa fa\r\n  0x0c067fff9d30: fd fd fd fa fa fa fd fd fd fa fa fa fd fd fd fa\r\n=&gt;0x0c067fff9d40: fa fa 00 00 00 fa fa fa[fd]fd fd fa fa fa fd fd\r\n  0x0c067fff9d50: fd fd fa fa 00 00 00 fa fa fa 00 00 00 fa fa fa\r\n  0x0c067fff9d60: 00 00 00 fa fa fa 00 00 00 00 fa fa 00 00 00 fa\r\n  0x0c067fff9d70: fa fa 00 00 00 fa fa fa 00 00 00 06 fa fa 00 00\r\n  0x0c067fff9d80: 01 fa fa fa 00 00 05 fa fa fa 00 00 00 fa fa fa\r\n  0x0c067fff9d90: 00 00 00 00 fa fa 00 00 00 00 fa fa 00 00 00 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==5430==ABORTING\r\n<\/font><\/pre>\n<p><strong>Affected version:<\/strong><br \/>\n1.9a<\/p>\n<p><strong>Fixed version:<\/strong><br \/>\n1.10<\/p>\n<p><strong>Commit fix:<\/strong><br \/>\n<a href=\"http:\/\/git.ghostscript.com\/?p=mupdf.git;h=1e03c06456d997435019fb3526fa2d4be7dbc6ec\">http:\/\/git.ghostscript.com\/?p=mupdf.git;h=1e03c06456d997435019fb3526fa2d4be7dbc6ec<\/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-2016-8674<\/p>\n<p><strong>Timeline:<\/strong><br \/>\n2016-08-05: bug discovered<br \/>\n2016-08-05: bug reported privately to upstream<br \/>\n2016-09-22: upstream released a patch<br \/>\n2016-09-22: blog post about the issue<br \/>\n2016-10-16: CVE Assigned<br \/>\n2016-10-21: upstream released 1.10<\/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=\"rHgerdOops\" class=\"wp-embedded-content\"><p><a href=\"http:\/\/blogs.gentoo.org\/ago\/2016\/09\/22\/mupdf-use-after-free-in-pdf_to_num-pdf-object-c\/\">mupdf: use-after-free in pdf_to_num (pdf-object.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\/2016\/09\/22\/mupdf-use-after-free-in-pdf_to_num-pdf-object-c\/embed\/#?secret=rHgerdOops\" data-secret=\"rHgerdOops\" width=\"600\" height=\"338\" title=\"&#8220;mupdf: use-after-free in pdf_to_num (pdf-object.c)&#8221; &#8212; agostino&#039;s blog\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Description: mupdf is a lightweight PDF viewer and toolkit written in portable C. A fuzzing through mutool revealed a use-after-free. The complete ASan output: # mutool info $FILE ==5430==ERROR: AddressSanitizer: heap-use-after-free on address 0x60300000ea42 at pc 0x7fbc4c3824e5 bp 0x7ffee68ead70 sp &hellip; <a href=\"https:\/\/blogs.gentoo.org\/ago\/2016\/09\/22\/mupdf-use-after-free-in-pdf_to_num-pdf-object-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-9Q","_links":{"self":[{"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/posts\/610"}],"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=610"}],"version-history":[{"count":5,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/posts\/610\/revisions"}],"predecessor-version":[{"id":989,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/posts\/610\/revisions\/989"}],"wp:attachment":[{"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/media?parent=610"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/categories?post=610"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/tags?post=610"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}