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.

X.Org X server before 1.13.4 and 1.4.x before 1.14.1 does not properly restrict access to input events when adding a new hot-plug device, which might allow physically proximate attackers to obtain sensitive information, as demonstrated by reading passwords from a tty.

The ProcSetEventMask function in difs/events.c in the xfs font server for X.Org X11R6 through X11R6.6 and XFree86 before 3.3.3 calls the SendErrToClient function with a mask value instead of a pointer, which allows local users to cause a denial of service (memory corruption and crash) or obtain potentially sensitive information from memory via a SetEventMask request that triggers an invalid pointer dereference.

The GLX extension in X.Org xserver 1.7.7 allows remote authenticated users to cause a denial of service (server crash) and possibly execute arbitrary code via (1) a crafted request that triggers a client swap in glx/glxcmdsswap.c; or (2) a crafted length or (3) a negative value in the screen field in a request to glx/glxcmds.c.

The ProcRenderAddGlyphs function in the Render extension (render/render.c) in X.Org xserver 1.7.7 and earlier allows local users to read arbitrary memory and possibly cause a denial of service (server crash) via unspecified vectors related to an "input sanitization flaw."

The fbComposite function in fbpict.c in the Render extension in the X server in X.Org X11R7.1 allows remote authenticated users to cause a denial of service (memory corruption and daemon crash) or possibly execute arbitrary code via a crafted request, related to an incorrect macro definition.

Integer overflow in the ProcRenderAddGlyphs function in the Render extension for X.Org 6.8.2, 6.9.0, 7.0, and 7.1, and XFree86 X server, allows local users to execute arbitrary code via a crafted X protocol request that triggers memory corruption during processing of glyph management data structures.

Integer overflow in the ProcDbeGetVisualInfo function in the DBE extension for X.Org 6.8.2, 6.9.0, 7.0, and 7.1, and XFree86 X server, allows local users to execute arbitrary code via a crafted X protocol request that triggers memory corruption during processing of unspecified data structures.

Integer overflow in the ProcDbeSwapBuffers function in the DBE extension for X.Org 6.8.2, 6.9.0, 7.0, and 7.1, and XFree86 X server, allows local users to execute arbitrary code via a crafted X protocol request that triggers memory corruption during processing of unspecified data structures.