{"id":1697,"date":"2017-04-29T16:12:44","date_gmt":"2017-04-29T14:12:44","guid":{"rendered":"http:\/\/blogs.gentoo.org\/ago\/?p=1697"},"modified":"2017-05-07T12:03:03","modified_gmt":"2017-05-07T10:03:03","slug":"libpcre-heap-based-buffer-overflow-write-in-pcre2test-c","status":"publish","type":"post","link":"https:\/\/blogs.gentoo.org\/ago\/2017\/04\/29\/libpcre-heap-based-buffer-overflow-write-in-pcre2test-c\/","title":{"rendered":"libpcre: heap-based buffer overflow write in pcre2test.c"},"content":{"rendered":"<p><strong>Description<\/strong>:<br \/>\n<a href=\"http:\/\/www.pcre.org\">libpcre<\/a> is a perl-compatible regular expression library.<\/p>\n<p>A fuzz on pcre2 via pcre2test revealed an overflow in that command-line utility.<\/p>\n<pre><font size=\"2\"># pcre2test -d -i -32 $FILE\r\n==30932==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61100000a000 at pc 0x7f2d8c3aea0f bp 0x7ffeea6b6e20 sp 0x7ffeea6b6e18                                                                         \r\nWRITE of size 4 at 0x61100000a000 thread T0                                                                                                                                                                       \r\n    #0 0x7f2d8c3aea0e in pcre2_get_error_message_32 \/tmp\/portage\/dev-libs\/libpcre2-10.23\/work\/pcre2-10.23\/src\/pcre2_error.c:318:13                                                                                \r\n    #1 0x53b7c5 in process_pattern \/tmp\/portage\/dev-libs\/libpcre2-10.23\/work\/pcre2-10.23\/src\/pcre2test.c:5169:3                                                                                                   \r\n    #2 0x513846 in main \/tmp\/portage\/dev-libs\/libpcre2-10.23\/work\/pcre2-10.23\/src\/pcre2test.c:7839:10                                                                                                             \r\n    #3 0x7f2d8b37478f in __libc_start_main \/tmp\/portage\/sys-libs\/glibc-2.23-r3\/work\/glibc-2.23\/csu\/..\/csu\/libc-start.c:289                                                                                        \r\n    #4 0x41d5b8 in _init (\/usr\/bin\/pcre2test+0x41d5b8)                                                                                                                                                            \r\n                                                                                                                                                                                                                  \r\n0x61100000a000 is located 0 bytes to the right of 256-byte region [0x611000009f00,0x61100000a000)                                                                                                                 \r\nallocated by thread T0 here:                                                                                                                                                                                      \r\n    #0 0x4d6378 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 0x54c522 in to32 \/tmp\/portage\/dev-libs\/libpcre2-10.23\/work\/pcre2-10.23\/src\/pcre2test.c:2911:27                                                                                                             \r\n    #2 0x53962e in process_pattern \/tmp\/portage\/dev-libs\/libpcre2-10.23\/work\/pcre2-10.23\/src\/pcre2test.c:4998:43                                                                                                  \r\n    #3 0x513846 in main \/tmp\/portage\/dev-libs\/libpcre2-10.23\/work\/pcre2-10.23\/src\/pcre2test.c:7839:10                                                                                                             \r\n    #4 0x7f2d8b37478f 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\/dev-libs\/libpcre2-10.23\/work\/pcre2-10.23\/src\/pcre2_error.c:318:13 in pcre2_get_error_message_32                                                      \r\nShadow bytes around the buggy address:                                                                                                                                                                            \r\n  0x0c227fff93b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa\r\n  0x0c227fff93c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa\r\n  0x0c227fff93d0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa\r\n  0x0c227fff93e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\r\n  0x0c227fff93f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\r\n=&gt;0x0c227fff9400:[fa]fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa\r\n  0x0c227fff9410: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa\r\n  0x0c227fff9420: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa\r\n  0x0c227fff9430: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa\r\n  0x0c227fff9440: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa\r\n  0x0c227fff9450: 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==30932==ABORTING\r\n<\/font><\/pre>\n<p><strong>Affected version:<\/strong><br \/>\n10.23<\/p>\n<p><strong>Fixed version:<\/strong><br \/>\nN\/A<\/p>\n<p><strong>Commit fix:<\/strong><br \/>\n<a href=\"https:\/\/vcs.pcre.org\/pcre2\/code\/trunk\/src\/pcre2test.c?r1=692&amp;r2=697\">https:\/\/vcs.pcre.org\/pcre2\/code\/trunk\/src\/pcre2test.c?r1=692&amp;r2=697<\/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-2017-8786<\/p>\n<p><strong>Reproducer:<\/strong><br \/>\n<a href=\"https:\/\/github.com\/asarubbo\/poc\/blob\/master\/00220-pcre2-heapoverflow-pcre2_get_error_message_32\">https:\/\/github.com\/asarubbo\/poc\/blob\/master\/00220-pcre2-heapoverflow-pcre2_get_error_message_32<\/a><\/p>\n<p><strong>Timeline:<\/strong><br \/>\n2017-03-17: bug discovered and reported to upstream<br \/>\n2017-03-21: upstream released a patch<br \/>\n2017-04-29: blog post about the issue<br \/>\n2017-05-05: 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=\"hgKVpNeqDx\" class=\"wp-embedded-content\"><p><a href=\"http:\/\/blogs.gentoo.org\/ago\/2017\/04\/29\/libpcre-heap-based-buffer-overflow-write-in-pcre2test-c\/\">libpcre: heap-based buffer overflow write in pcre2test.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\/29\/libpcre-heap-based-buffer-overflow-write-in-pcre2test-c\/embed\/#?secret=hgKVpNeqDx\" data-secret=\"hgKVpNeqDx\" width=\"600\" height=\"338\" title=\"&#8220;libpcre: heap-based buffer overflow write in pcre2test.c&#8221; &#8212; agostino&#039;s blog\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Description: libpcre is a perl-compatible regular expression library. A fuzz on pcre2 via pcre2test revealed an overflow in that command-line utility. # pcre2test -d -i -32 $FILE ==30932==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x61100000a000 at pc 0x7f2d8c3aea0f bp 0x7ffeea6b6e20 sp 0x7ffeea6b6e18 &hellip; <a href=\"https:\/\/blogs.gentoo.org\/ago\/2017\/04\/29\/libpcre-heap-based-buffer-overflow-write-in-pcre2test-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-rn","_links":{"self":[{"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/posts\/1697"}],"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=1697"}],"version-history":[{"count":4,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/posts\/1697\/revisions"}],"predecessor-version":[{"id":1756,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/posts\/1697\/revisions\/1756"}],"wp:attachment":[{"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/media?parent=1697"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/categories?post=1697"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.gentoo.org\/ago\/wp-json\/wp\/v2\/tags?post=1697"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}