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) __