From 5ad707ddf33d1d785a8ca1fbeec91d2eee985820 Mon Sep 17 00:00:00 2001 From: Hardening Date: Fri, 6 Jun 2014 23:24:16 +0200 Subject: [PATCH] Fix CVE-2014-0250 This patch fixes CVE-2014-0250 by checking width, height and bpp when receiving a new pointer. --- client/X11/xf_cliprdr.c | 11 +++++-- libfreerdp/core/fastpath.c | 2 +- libfreerdp/core/orders.c | 21 ++++++++++++ libfreerdp/core/surface.c | 6 ++++ libfreerdp/core/update.c | 82 +++++++++++++++++++++++++++++++++++++++------- libfreerdp/core/update.h | 2 +- libfreerdp/core/window.c | 5 +++ 7 files changed, 114 insertions(+), 15 deletions(-) diff --git a/client/X11/xf_cliprdr.c b/client/X11/xf_cliprdr.c index 19c4332..8fb49f9 100644 --- a/client/X11/xf_cliprdr.c +++ b/client/X11/xf_cliprdr.c @@ -914,7 +914,7 @@ static void xf_cliprdr_process_unicodetext(clipboardContext* cb, BYTE* data, int crlf2lf(cb->data, &cb->data_length); } -static void xf_cliprdr_process_dib(clipboardContext* cb, BYTE* data, int size) +static BOOL xf_cliprdr_process_dib(clipboardContext* cb, BYTE* data, int size) { wStream* s; UINT16 bpp; @@ -926,12 +926,18 @@ static void xf_cliprdr_process_dib(clipboardContext* cb, BYTE* data, int size) if (size < 40) { DEBUG_X11_CLIPRDR("dib size %d too short", size); - return; + return FALSE; } s = Stream_New(data, size); Stream_Seek(s, 14); Stream_Read_UINT16(s, bpp); + if ((bpp < 1) || (bpp > 32)) + { + fprintf(stderr, "%s: invalid bpp value %d", __FUNCTION__, bpp); + return FALSE; + } + Stream_Read_UINT32(s, ncolors); offset = 14 + 40 + (bpp <= 8 ? (ncolors == 0 ? (1 << bpp) : ncolors) * 4 : 0); Stream_Free(s, FALSE); @@ -949,6 +955,7 @@ static void xf_cliprdr_process_dib(clipboardContext* cb, BYTE* data, int size) cb->data = Stream_Buffer(s); cb->data_length = Stream_GetPosition(s); Stream_Free(s, FALSE); + return TRUE; } static void xf_cliprdr_process_html(clipboardContext* cb, BYTE* data, int size) diff --git a/libfreerdp/core/fastpath.c b/libfreerdp/core/fastpath.c index 8448160..dcc7117 100644 --- a/libfreerdp/core/fastpath.c +++ b/libfreerdp/core/fastpath.c @@ -254,7 +254,7 @@ static int fastpath_recv_update(rdpFastPath* fastpath, BYTE updateCode, UINT32 s break; case FASTPATH_UPDATETYPE_COLOR: - if (!update_read_pointer_color(s, &pointer->pointer_color)) + if (!update_read_pointer_color(s, &pointer->pointer_color, 24)) return -1; IFCALL(pointer->PointerColor, context, &pointer->pointer_color); break; diff --git a/libfreerdp/core/orders.c b/libfreerdp/core/orders.c index e5cc520..f22407f 100644 --- a/libfreerdp/core/orders.c +++ b/libfreerdp/core/orders.c @@ -1830,6 +1830,11 @@ BOOL update_read_cache_bitmap_order(wStream* s, CACHE_BITMAP_ORDER* cache_bitmap Stream_Read_UINT8(s, cache_bitmap->bitmapWidth); /* bitmapWidth (1 byte) */ Stream_Read_UINT8(s, cache_bitmap->bitmapHeight); /* bitmapHeight (1 byte) */ Stream_Read_UINT8(s, cache_bitmap->bitmapBpp); /* bitmapBpp (1 byte) */ + if ((cache_bitmap->bitmapBpp < 1) || (cache_bitmap->bitmapBpp > 32)) + { + fprintf(stderr, "%s: invalid bitmap bpp %d\n", __FUNCTION__, cache_bitmap->bitmapBpp); + return FALSE; + } Stream_Read_UINT16(s, cache_bitmap->bitmapLength); /* bitmapLength (2 bytes) */ Stream_Read_UINT16(s, cache_bitmap->cacheIndex); /* cacheIndex (2 bytes) */ @@ -2068,6 +2073,11 @@ BOOL update_read_cache_bitmap_v3_order(wStream* s, CACHE_BITMAP_V3_ORDER* cache_ bitmapData = &cache_bitmap_v3->bitmapData; Stream_Read_UINT8(s, bitmapData->bpp); + if ((bitmapData->bpp < 1) || (bitmapData->bpp > 32)) + { + fprintf(stderr, "%s: invalid bpp value %d", __FUNCTION__, bitmapData->bpp); + return FALSE; + } Stream_Seek_UINT8(s); /* reserved1 (1 byte) */ Stream_Seek_UINT8(s); /* reserved2 (1 byte) */ Stream_Read_UINT8(s, bitmapData->codecID); /* codecID (1 byte) */ @@ -2672,6 +2682,11 @@ BOOL update_read_create_nine_grid_bitmap_order(wStream* s, CREATE_NINE_GRID_BITM return FALSE; Stream_Read_UINT8(s, create_nine_grid_bitmap->bitmapBpp); /* bitmapBpp (1 byte) */ + if ((create_nine_grid_bitmap->bitmapBpp < 1) || (create_nine_grid_bitmap->bitmapBpp > 32)) + { + fprintf(stderr, "%s: invalid bpp value %d", __FUNCTION__, create_nine_grid_bitmap->bitmapBpp); + return FALSE; + } Stream_Read_UINT16(s, create_nine_grid_bitmap->bitmapId); /* bitmapId (2 bytes) */ nineGridInfo = &(create_nine_grid_bitmap->nineGridInfo); @@ -2707,6 +2722,12 @@ BOOL update_read_stream_bitmap_first_order(wStream* s, STREAM_BITMAP_FIRST_ORDER Stream_Read_UINT8(s, stream_bitmap_first->bitmapFlags); /* bitmapFlags (1 byte) */ Stream_Read_UINT8(s, stream_bitmap_first->bitmapBpp); /* bitmapBpp (1 byte) */ + if ((stream_bitmap_first->bitmapBpp < 1) || (stream_bitmap_first->bitmapBpp > 32)) + { + fprintf(stderr, "%s: invalid bpp value %d", __FUNCTION__, stream_bitmap_first->bitmapBpp); + return FALSE; + } + Stream_Read_UINT16(s, stream_bitmap_first->bitmapType); /* bitmapType (2 bytes) */ Stream_Read_UINT16(s, stream_bitmap_first->bitmapWidth); /* bitmapWidth (2 bytes) */ Stream_Read_UINT16(s, stream_bitmap_first->bitmapHeight); /* bitmapHeigth (2 bytes) */ diff --git a/libfreerdp/core/surface.c b/libfreerdp/core/surface.c index 7d0fb22..992a3dd 100644 --- a/libfreerdp/core/surface.c +++ b/libfreerdp/core/surface.c @@ -38,6 +38,12 @@ static int update_recv_surfcmd_surface_bits(rdpUpdate* update, wStream* s, UINT3 Stream_Read_UINT16(s, cmd->destRight); Stream_Read_UINT16(s, cmd->destBottom); Stream_Read_UINT8(s, cmd->bpp); + if ((cmd->bpp < 1) || (cmd->bpp > 32)) + { + fprintf(stderr, "%s: invalid bpp value %d", __FUNCTION__, cmd->bpp); + return FALSE; + } + Stream_Seek(s, 2); /* reserved1, reserved2 */ Stream_Read_UINT8(s, cmd->codecID); Stream_Read_UINT16(s, cmd->width); diff --git a/libfreerdp/core/update.c b/libfreerdp/core/update.c index c4eaede..27c36e3 100644 --- a/libfreerdp/core/update.c +++ b/libfreerdp/core/update.c @@ -219,16 +219,32 @@ BOOL update_read_pointer_system(wStream* s, POINTER_SYSTEM_UPDATE* pointer_syste return TRUE; } -BOOL update_read_pointer_color(wStream* s, POINTER_COLOR_UPDATE* pointer_color) +BOOL update_read_pointer_color(wStream* s, POINTER_COLOR_UPDATE* pointer_color, int xorBpp) { + BYTE *newMask; + int scanlineSize; + if (Stream_GetRemainingLength(s) < 14) return FALSE; Stream_Read_UINT16(s, pointer_color->cacheIndex); /* cacheIndex (2 bytes) */ Stream_Read_UINT16(s, pointer_color->xPos); /* xPos (2 bytes) */ Stream_Read_UINT16(s, pointer_color->yPos); /* yPos (2 bytes) */ + + /** + * As stated in 2.2.9.1.1.4.4 Color Pointer Update: + * The maximum allowed pointer width/height is 96 pixels if the client indicated support + * for large pointers by setting the LARGE_POINTER_FLAG (0x00000001) in the Large + * Pointer Capability Set (section 2.2.7.2.7). If the LARGE_POINTER_FLAG was not + * set, the maximum allowed pointer width/height is 32 pixels. + * + * So we check for a maximum of 96 for CVE-2014-0250. + */ Stream_Read_UINT16(s, pointer_color->width); /* width (2 bytes) */ Stream_Read_UINT16(s, pointer_color->height); /* height (2 bytes) */ + if ((pointer_color->width > 96) || (pointer_color->height > 96)) + return FALSE; + Stream_Read_UINT16(s, pointer_color->lengthAndMask); /* lengthAndMask (2 bytes) */ Stream_Read_UINT16(s, pointer_color->lengthXorMask); /* lengthXorMask (2 bytes) */ @@ -245,26 +261,65 @@ BOOL update_read_pointer_color(wStream* s, POINTER_COLOR_UPDATE* pointer_color) if (pointer_color->lengthXorMask > 0) { + /** + * Spec states that: + * + * xorMaskData (variable): A variable-length array of bytes. Contains the 24-bpp, bottom-up + * XOR mask scan-line data. The XOR mask is padded to a 2-byte boundary for each encoded + * scan-line. For example, if a 3x3 pixel cursor is being sent, then each scan-line will consume 10 + * bytes (3 pixels per scan-line multiplied by 3 bytes per pixel, rounded up to the next even + * number of bytes). + * + * In fact instead of 24-bpp, the bpp parameter is given by the containing packet. + */ if (Stream_GetRemainingLength(s) < pointer_color->lengthXorMask) return FALSE; - if (!pointer_color->xorMaskData) - pointer_color->xorMaskData = malloc(pointer_color->lengthXorMask); - else - pointer_color->xorMaskData = realloc(pointer_color->xorMaskData, pointer_color->lengthXorMask); + scanlineSize = (7 + xorBpp * pointer_color->width) / 8; + scanlineSize = ((scanlineSize + 1) / 2) * 2; + if (scanlineSize * pointer_color->height != pointer_color->lengthXorMask) + { + fprintf(stderr, "%s: invalid lengthXorMask: width=%d height=%d, %d instead of %d\n", __FUNCTION__, + pointer_color->width, pointer_color->height, + pointer_color->lengthXorMask, scanlineSize * pointer_color->height); + return FALSE; + } + + newMask = realloc(pointer_color->xorMaskData, pointer_color->lengthXorMask); + if (!newMask) + return FALSE; + + pointer_color->xorMaskData = newMask; Stream_Read(s, pointer_color->xorMaskData, pointer_color->lengthXorMask); } if (pointer_color->lengthAndMask > 0) { + /** + * andMaskData (variable): A variable-length array of bytes. Contains the 1-bpp, bottom-up + * AND mask scan-line data. The AND mask is padded to a 2-byte boundary for each encoded + * scan-line. For example, if a 7x7 pixel cursor is being sent, then each scan-line will consume 2 + * bytes (7 pixels per scan-line multiplied by 1 bpp, rounded up to the next even number of + * bytes). + */ if (Stream_GetRemainingLength(s) < pointer_color->lengthAndMask) return FALSE; - if (!pointer_color->andMaskData) - pointer_color->andMaskData = malloc(pointer_color->lengthAndMask); - else - pointer_color->andMaskData = realloc(pointer_color->andMaskData, pointer_color->lengthAndMask); + scanlineSize = ((7 + pointer_color->width) / 8); + scanlineSize = ((1 + scanlineSize) / 2) * 2; + if (scanlineSize * pointer_color->height != pointer_color->lengthAndMask) + { + fprintf(stderr, "%s: invalid lengthAndMask: %d instead of %d\n", __FUNCTION__, + pointer_color->lengthAndMask, scanlineSize * pointer_color->height); + return FALSE; + } + + newMask = realloc(pointer_color->andMaskData, pointer_color->lengthAndMask); + if (!newMask) + return FALSE; + + pointer_color->andMaskData = newMask; Stream_Read(s, pointer_color->andMaskData, pointer_color->lengthAndMask); } @@ -281,7 +336,12 @@ BOOL update_read_pointer_new(wStream* s, POINTER_NEW_UPDATE* pointer_new) return FALSE; Stream_Read_UINT16(s, pointer_new->xorBpp); /* xorBpp (2 bytes) */ - return update_read_pointer_color(s, &pointer_new->colorPtrAttr); /* colorPtrAttr */ + if ((pointer_new->xorBpp < 1) || (pointer_new->xorBpp > 32)) + { + fprintf(stderr, "%s: invalid xorBpp %d\n", __FUNCTION__, pointer_new->xorBpp); + return FALSE; + } + return update_read_pointer_color(s, &pointer_new->colorPtrAttr, pointer_new->xorBpp); /* colorPtrAttr */ } BOOL update_read_pointer_cached(wStream* s, POINTER_CACHED_UPDATE* pointer_cached) @@ -320,7 +380,7 @@ BOOL update_recv_pointer(rdpUpdate* update, wStream* s) break; case PTR_MSG_TYPE_COLOR: - if (!update_read_pointer_color(s, &pointer->pointer_color)) + if (!update_read_pointer_color(s, &pointer->pointer_color, 24)) return FALSE; IFCALL(pointer->PointerColor, context, &pointer->pointer_color); break; diff --git a/libfreerdp/core/update.h b/libfreerdp/core/update.h index c3088f2..d6c2d59 100644 --- a/libfreerdp/core/update.h +++ b/libfreerdp/core/update.h @@ -53,7 +53,7 @@ BOOL update_recv(rdpUpdate* update, wStream* s); BOOL update_read_pointer_position(wStream* s, POINTER_POSITION_UPDATE* pointer_position); BOOL update_read_pointer_system(wStream* s, POINTER_SYSTEM_UPDATE* pointer_system); -BOOL update_read_pointer_color(wStream* s, POINTER_COLOR_UPDATE* pointer_color); +BOOL update_read_pointer_color(wStream* s, POINTER_COLOR_UPDATE* pointer_color, int xorBpp); BOOL update_read_pointer_new(wStream* s, POINTER_NEW_UPDATE* pointer_new); BOOL update_read_pointer_cached(wStream* s, POINTER_CACHED_UPDATE* pointer_cached); diff --git a/libfreerdp/core/window.c b/libfreerdp/core/window.c index 7422f5b..c10fa33 100644 --- a/libfreerdp/core/window.c +++ b/libfreerdp/core/window.c @@ -35,6 +35,11 @@ BOOL update_read_icon_info(wStream* s, ICON_INFO* icon_info) Stream_Read_UINT16(s, icon_info->cacheEntry); /* cacheEntry (2 bytes) */ Stream_Read_UINT8(s, icon_info->cacheId); /* cacheId (1 byte) */ Stream_Read_UINT8(s, icon_info->bpp); /* bpp (1 byte) */ + if ((icon_info->bpp < 1) || (icon_info->bpp > 32)) + { + fprintf(stderr, "%s: invalid bpp %d\n", __FUNCTION__, icon_info->bpp); + return FALSE; + } Stream_Read_UINT16(s, icon_info->width); /* width (2 bytes) */ Stream_Read_UINT16(s, icon_info->height); /* height (2 bytes) */ -- 1.9.3