xorg-x11-server before 1.19.5 was missing extra length validation in ProcEstablishConnection function allowing malicious X client to cause X server to crash or possibly execute arbitrary code.

xorg-x11-server before 1.19.5 was missing length validation in MIT-SCREEN-SAVER extension allowing malicious X client to cause X server to crash or possibly execute arbitrary code.

libXcursor before 1.1.15 has various integer overflows that could lead to heap buffer overflows when processing malicious cursors, e.g., with programs like GIMP. It is also possible that an attack vector exists against the related code in cursor/xcursor.c in Wayland through 1.14.0.

In libXfont before 1.5.4 and libXfont2 before 2.0.3, a local attacker can open (but not read) files on the system as root, triggering tape rewinds, watchdogs, or similar mechanisms that can be triggered by opening files.

In the pcfGetProperties function in bitmap/pcfread.c in libXfont through 1.5.2 and 2.x before 2.0.2, a missing boundary check (for PCF files) could be used by local attackers authenticated to an Xserver for a buffer over-read, for information disclosure or a crash of the X server.

In the PatternMatch function in fontfile/fontdir.c in libXfont through 1.5.2 and 2.x before 2.0.2, an attacker with access to an X connection can cause a buffer over-read during pattern matching of fonts, leading to information disclosure or a crash (denial of service). This occurs because '\0' characters are incorrectly skipped in situations involving ? characters.

In X.Org Server (aka xserver and xorg-server) before 1.19.4, a local attacker authenticated to the X server could overflow a global buffer, causing crashes of the X server or potentially other problems by injecting large or malformed XKB related atoms and accessing them via xkbcomp.

In X.Org Server (aka xserver and xorg-server) before 1.19.4, an attacker authenticated to an X server with the X shared memory extension enabled can cause aborts of the X server or replace shared memory segments of other X clients in the same session.

A single byte overflow in catalogue.c in X.Org libXfont 1.3.1 allows remote attackers to have unspecified impact.

Uninitialized data in endianness conversion in the XEvent handling of the X.Org X Server before 2017-06-19 allowed authenticated malicious users to access potentially privileged data from the X server.

In the X.Org X server before 2017-06-19, a user authenticated to an X Session could crash or execute code in the context of the X Server by exploiting a stack overflow in the endianness conversion of X Events.

Multiple integer overflows in libXpm before 3.5.12, when a program requests parsing XPM extensions on a 64-bit platform, allow remote attackers to cause a denial of service (out-of-bounds write) or execute arbitrary code via (1) the number of extensions or (2) their concatenated length in a crafted XPM file, which triggers a heap-based buffer overflow.

Buffer underflow in X.org libXvMC before 1.0.10 allows remote X servers to have unspecified impact via an empty string.

The XRenderQueryFilters function in X.org libXrender before 0.9.10 allows remote X servers to trigger out-of-bounds write operations via vectors involving filter name lengths.

Multiple integer overflows in X.org libXi before 1.7.7 allow remote X servers to cause a denial of service (out-of-bounds memory access or infinite loop) via vectors involving length fields.

Integer overflow in X.org libXfixes before 5.0.3 on 32-bit platforms might allow remote X servers to gain privileges via a length value of INT_MAX, which triggers the client to stop reading data and get out of sync.

X.org libXtst before 1.2.3 allows remote X servers to cause a denial of service (infinite loop) via a reply in the (1) XRecordStartOfData, (2) XRecordEndOfData, or (3) XRecordClientDied category without a client sequence and with attached data.

Multiple buffer overflows in the (1) XvQueryAdaptors and (2) XvQueryEncodings functions in X.org libXrender before 0.9.10 allow remote X servers to trigger out-of-bounds write operations via vectors involving length fields.

The XListFonts function in X.org libX11 before 1.6.4 might allow remote X servers to gain privileges via vectors involving length fields, which trigger out-of-bounds write operations.

X.org libXrandr before 1.5.1 allows remote X servers to trigger out-of-bounds write operations by leveraging mishandling of reply data.

Multiple integer overflows in X.org libXrandr before 1.5.1 allow remote X servers to trigger out-of-bounds write operations via a crafted response.

The XGetImage function in X.org libX11 before 1.6.4 might allow remote X servers to gain privileges via vectors involving image type and geometry, which triggers out-of-bounds read operations.

The (1) XvQueryAdaptors and (2) XvQueryEncodings functions in X.org libXv before 1.0.11 allow remote X servers to trigger out-of-bounds memory access operations via vectors involving length specifications in received data.

X.org libXi before 1.7.7 allows remote X servers to cause a denial of service (infinite loop) via vectors involving length fields.

Multiple integer overflows in X.org libXtst before 1.2.3 allow remote X servers to trigger out-of-bounds memory access operations by leveraging the lack of range checks.

The ProcPutImage function in dix/dispatch.c in X.Org Server (aka xserver and xorg-server) before 1.16.4 allows attackers to cause a denial of service (divide-by-zero and crash) via a zero-height PutImage request.

The authentication setup in XWayland 1.16.x and 1.17.x before 1.17.2 starts the server in non-authenticating mode, which allows local users to read from or send information to arbitrary X11 clients via vectors involving a UNIX socket.

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 bdfReadCharacters function in bitmap/bdfread.c in X.Org libXfont before 1.4.9 and 1.5.x before 1.5.1 does not properly perform type conversion for metrics values, which allows remote authenticated users to cause a denial of service (out-of-bounds memory access) and possibly execute arbitrary code via a crafted BDF font file.

The bdfReadProperties function in bitmap/bdfread.c in X.Org libXfont before 1.4.9 and 1.5.x before 1.5.1 allows remote authenticated users to cause a denial of service (out-of-bounds write and crash) or possibly execute arbitrary code via a (1) negative or (2) large property count in a BDF font file.

The bdfReadCharacters function in bitmap/bdfread.c in X.Org libXfont before 1.4.9 and 1.5.x before 1.5.1 does not properly handle character bitmaps it cannot read, which allows remote authenticated users to cause a denial of service (NULL pointer dereference and crash) and possibly execute arbitrary code via a crafted BDF font file.

X.Org Server (aka xserver and xorg-server) before 1.16.3 and 1.17.x before 1.17.1 allows remote attackers to obtain sensitive information from process memory or cause a denial of service (crash) via a crafted string length value in a XkbSetGeometry request.

The XInput extension in X.Org X Window System (aka X11 or X) X11R4 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) SProcXChangeDeviceControl, (2) ProcXChangeDeviceControl, (3) ProcXChangeFeedbackControl, (4) ProcXSendExtensionEvent, (5) SProcXIAllowEvents, (6) SProcXIChangeCursor, (7) ProcXIChangeHierarchy, (8) SProcXIGetClientPointer, (9) SProcXIGrabDevice, (10) SProcXIUngrabDevice, (11) ProcXIUngrabDevice, (12) SProcXIPassiveGrabDevice, (13) ProcXIPassiveGrabDevice, (14) SProcXIPassiveUngrabDevice, (15) ProcXIPassiveUngrabDevice, (16) SProcXListDeviceProperties, (17) SProcXDeleteDeviceProperty, (18) SProcXIListProperties, (19) SProcXIDeleteProperty, (20) SProcXIGetProperty, (21) SProcXIQueryDevice, (22) SProcXIQueryPointer, (23) SProcXISelectEvents, (24) SProcXISetClientPointer, (25) SProcXISetFocus, (26) SProcXIGetFocus, or (27) SProcXIWarpPointer function.

The SProcXCMiscGetXIDList function in the XC-MISC extension in X.Org X Window System (aka X11 or X) X11R6.0 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.

X.Org X Window System (aka X11 and X) X11R5 and X.Org Server (aka xserver and xorg-server) before 1.16.3, when using SUN-DES-1 (Secure RPC) authentication credentials, does not check the return value of a malloc call, which allows remote attackers to cause a denial of service (NULL pointer dereference and server crash) via a crafted connection request.

Integer overflow in the ProcDRI2GetBuffers function in the DRI2 extension in X.Org Server (aka xserver and xorg-server) 1.7.0 through 1.16.x before 1.16.3 allows remote authenticated users to cause a denial of service (crash) or possibly execute arbitrary code via a crafted request, which triggers an out-of-bounds read or write.

The DBE extension in X.Org X Window System (aka X11 or X) X11R6.1 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) ProcDbeSwapBuffers or (2) SProcDbeSwapBuffers function.

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 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_GetTexImage, (25) __glXDisp_GetPolygonStipple, (26) __glXDispSwap_GetPolygonStipple, (27) __glXDisp_GetSeparableFilter, (28) __glXDisp_GetSeparableFilterEXT, (29) __glXDisp_GetConvolutionFilter, (30) __glXDisp_GetConvolutionFilterEXT, (31) __glXDisp_GetHistogram, (32) __glXDisp_GetHistogramEXT, (33) __glXDisp_GetMinmax, (34) __glXDisp_GetMinmaxEXT, (35) __glXDisp_GetColorTable, (36) __glXDisp_GetColorTableSGI, (37) GetSeparableFilter, (38) GetConvolutionFilter, (39) GetHistogram, (40) GetMinmax, or (41) GetColorTable function.

Multiple integer overflows in X.Org X Window System (aka X11 or X) X11R1 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) ProcPutImage, (2) GetHosts, (3) RegionSizeof, or (4) REQUEST_FIXED_SIZE function, which triggers an out-of-bounds read or write.

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.

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.

X.Org Server (aka xserver and xorg-server) 1.15.0 through 1.16.x 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) sproc_dri3_query_version, (2) sproc_dri3_open, (3) sproc_dri3_pixmap_from_buffer, (4) sproc_dri3_buffer_from_pixmap, (5) sproc_dri3_fence_from_fd, (6) sproc_dri3_fd_from_fence, (7) proc_present_query_capabilities, (8) sproc_present_query_version, (9) sproc_present_pixmap, (10) sproc_present_notify_msc, (11) sproc_present_select_input, or (12) sproc_present_query_capabilities function in the (a) DRI3 or (b) Present extension.

The SProcXFixesSelectSelectionInput function in the XFixes extension in X.Org X Window System (aka X11 or X) X11R6.8.0 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 value.

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.

Directory traversal vulnerability in tools/backlight_helper.c in X.Org xf86-video-intel 2.99.911 allows remote attackers to create or overwrite arbitrary files via a .. (dot dot) in the interface name.

Multiple integer overflows in the (1) FontFileAddEntry and (2) lexAlias functions in X.Org libXfont before 1.4.8 and 1.4.9x before 1.4.99.901 might allow local users to gain privileges by adding a directory with a large fonts.dir or fonts.alias file to the font path, which triggers a heap-based buffer overflow, related to metadata.

Multiple buffer overflows in X.Org libXfont before 1.4.8 and 1.4.9x before 1.4.99.901 allow remote font servers to execute arbitrary code via a crafted xfs protocol reply to the (1) _fs_recv_conn_setup, (2) fs_read_open_font, (3) fs_read_query_info, (4) fs_read_extent_info, (5) fs_read_glyphs, (6) fs_read_list, or (7) fs_read_list_info function.

Multiple integer overflows in the (1) fs_get_reply, (2) fs_alloc_glyphs, and (3) fs_read_extent_info functions in X.Org libXfont before 1.4.8 and 1.4.9x before 1.4.99.901 allow remote font servers to execute arbitrary code via a crafted xfs reply, which triggers a buffer overflow.

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.

The X.Org X wrapper (xserver-wrapper.c) in Debian GNU/Linux and Ubuntu Linux does not properly verify the TTY of a user who is starting X, which allows local users to bypass intended access restrictions by associating stdin with a file that is misinterpreted as the console TTY.