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.

The Xinput module (modules/im/ximcp/imLcIm.c) in X.Org libX11 1.0.2 and 1.0.3 opens a file for reading twice using the same file descriptor, which causes a file descriptor leak that allows local users to read files specified by the XCOMPOSEFILE environment variable via the duplicate file descriptor.

The Xsession script, as used by X Display Manager (xdm) in NetBSD before 20060212, X.Org before 20060317, and Solaris 8 through 10 before 20061006, allows local users to overwrite arbitrary files, or read another user's Xsession errors file, via a symlink attack on a /tmp/xses-$USER file.

Integer overflow in the CIDAFM function in X.Org 6.8.2 and XFree86 X server allows local users to execute arbitrary code via crafted Adobe Font Metrics (AFM) files with a modified number of character metrics (StartCharMetrics), which leads to a heap-based buffer overflow.

Integer overflow in the scan_cidfont function in X.Org 6.8.2 and XFree86 X server allows local users to execute arbitrary code via crafted (1) CMap and (2) CIDFont font data with modified item counts in the (a) begincodespacerange, (b) cidrange, and (c) notdefrange sections.

X.Org and XFree86, including libX11, xdm, xf86dga, xinit, xload, xtrans, and xterm, does not check the return values for setuid and seteuid calls when attempting to drop privileges, which might allow local users to gain privileges by causing those calls to fail, such as by exceeding a ulimit.

Buffer overflow in the X render (Xrender) extension in X.org X server 6.8.0 up to allows attackers to cause a denial of service (crash), as demonstrated by the (1) XRenderCompositeTriStrip and (2) XRenderCompositeTriFan requests in the rendertest from XCB xcb/xcb-demo, which leads to an incorrect memory allocation due to a typo in an expression that uses a "&" instead of a "*" operator. NOTE: the subject line of the original announcement used an incorrect CVE number for this issue.

X.Org server (xorg-server) 1.0.0 and later, X11R6.9.0, and X11R7.0 inadvertently treats the address of the geteuid function as if it is the return value of a call to geteuid, which allows local users to bypass intended restrictions and (1) execute arbitrary code via the -modulepath command line option or (2) overwrite arbitrary files via -logfile.

The XClientMessageEvent struct used in certain components of X.Org 6.8.2 and earlier, possibly including (1) the X server and (2) Xlib, uses a "long" specifier for elements of the l array, which results in inconsistent sizes in the struct on 32-bit versus 64-bit platforms, and might allow attackers to cause a denial of service (application crash) and possibly conduct other attacks.

scan.c for LibXPM may allow attackers to execute arbitrary code via a negative bitmap_unit value that leads to a buffer overflow.