Multiple off-by-one errors in the (1) MakeBigReq and (2) SetReqLen macros in include/X11/Xlibint.h in X11R6.x and libX11 before 1.6.0 allow remote attackers to have unspecified impact via a crafted request, which triggers a buffer overflow.

The Render extension in XFree86 4.0.1, X.Org X Window System (aka X11 or X) X11R6.7, and X.Org Server (aka xserver and xorg-server) before 1.16.3 allows remote authenticated users to cause a denial of service (out-of-bounds read or write) or possibly execute arbitrary code via a crafted length or index value to the (1) ProcRenderQueryVersion, (2) SProcRenderQueryVersion, (3) SProcRenderQueryPictFormats, (4) SProcRenderQueryPictIndexValues, (5) SProcRenderCreatePicture, (6) SProcRenderChangePicture, (7) SProcRenderSetPictureClipRectangles, (8) SProcRenderFreePicture, (9) SProcRenderComposite, (10) SProcRenderScale, (11) SProcRenderCreateGlyphSet, (12) SProcRenderReferenceGlyphSet, (13) SProcRenderFreeGlyphSet, (14) SProcRenderFreeGlyphs, or (15) SProcRenderCompositeGlyphs function.

The GLX extension in XFree86 4.0, X.Org X Window System (aka X11 or X) X11R6.7, and X.Org Server (aka xserver and xorg-server) before 1.16.3 allows remote authenticated users to cause a denial of service (out-of-bounds read or write) or possibly execute arbitrary code via a crafted length or index value to the (1) __glXDisp_Render, (2) __glXDisp_RenderLarge, (3) __glXDispSwap_VendorPrivate, (4) __glXDispSwap_VendorPrivateWithReply, (5) set_client_info, (6) __glXDispSwap_SetClientInfoARB, (7) DoSwapInterval, (8) DoGetProgramString, (9) DoGetString, (10) __glXDispSwap_RenderMode, (11) __glXDisp_GetCompressedTexImage, (12) __glXDispSwap_GetCompressedTexImage, (13) __glXDisp_FeedbackBuffer, (14) __glXDispSwap_FeedbackBuffer, (15) __glXDisp_SelectBuffer, (16) __glXDispSwap_SelectBuffer, (17) __glXDisp_Flush, (18) __glXDispSwap_Flush, (19) __glXDisp_Finish, (20) __glXDispSwap_Finish, (21) __glXDisp_ReadPixels, (22) __glXDispSwap_ReadPixels, (23) __glXDisp_GetTexImage, (24) __glXDispSwap_Get…

The XVideo extension in XFree86 4.0.0, X.Org X Window System (aka X11 or X) X11R6.7, and X.Org Server (aka xserver and xorg-server) before 1.16.3 allows remote authenticated users to cause a denial of service (out-of-bounds read or write) or possibly execute arbitrary code via a crafted length or index value to the (1) SProcXvQueryExtension, (2) SProcXvQueryAdaptors, (3) SProcXvQueryEncodings, (4) SProcXvGrabPort, (5) SProcXvUngrabPort, (6) SProcXvPutVideo, (7) SProcXvPutStill, (8) SProcXvGetVideo, (9) SProcXvGetStill, (10) SProcXvPutImage, (11) SProcXvShmPutImage, (12) SProcXvSelectVideoNotify, (13) SProcXvSelectPortNotify, (14) SProcXvStopVideo, (15) SProcXvSetPortAttribute, (16) SProcXvGetPortAttribute, (17) SProcXvQueryBestSize, (18) SProcXvQueryPortAttributes, (19) SProcXvQueryImageAttributes, or (20) SProcXvListImageFormats function.

The RandR extension in XFree86 4.2.0, X.Org X Window System (aka X11 or X) X11R6.7, and X.Org Server (aka xserver and xorg-server) before 1.16.3 allows remote authenticated users to cause a denial of service (out-of-bounds read or write) or possibly execute arbitrary code via a crafted length or index value to the (1) SProcRRQueryVersion, (2) SProcRRGetScreenInfo, (3) SProcRRSelectInput, or (4) SProcRRConfigureOutputProperty function.

Multiple integer overflows in the GLX extension in XFree86 4.0, X.Org X Window System (aka X11 or X) X11R6.7, and X.Org Server (aka xserver and xorg-server) before 1.16.3 allow remote authenticated users to cause a denial of service (crash) or possibly execute arbitrary code via a crafted request to the (1) __glXDisp_ReadPixels, (2) __glXDispSwap_ReadPixels, (3) __glXDisp_GetTexImage, (4) __glXDispSwap_GetTexImage, (5) GetSeparableFilter, (6) GetConvolutionFilter, (7) GetHistogram, (8) GetMinmax, (9) GetColorTable, (10) __glXGetAnswerBuffer, (11) __GLX_GET_ANSWER_BUFFER, (12) __glXMap1dReqSize, (13) __glXMap1fReqSize, (14) Map2Size, (15) __glXMap2dReqSize, (16) __glXMap2fReqSize, (17) __glXImageSize, or (18) __glXSeparableFilter2DReqSize function, which triggers an out-of-bounds read or write.

xkeyboard-config before 2.5 in X.Org before 7.6 enables certain XKB debugging functions by default, which allows physically proximate attackers to bypass an X screen lock via keyboard combinations that break the input grab.

Use-after-free vulnerability in the doImageText function in dix/dixfonts.c in the xorg-server module before 1.14.4 in X.Org X11 allows remote authenticated users to cause a denial of service (daemon crash) or possibly execute arbitrary code via a crafted ImageText request that triggers memory-allocation failure.