xemacs: multiple integer overflow flaws

Multiple integer overflows in glyphs-eimage.c in XEmacs 21.4.22, when running on Windows, allow remote attackers to cause a denial of service (crash) or execute arbitrary code via (1) the tiff_instantiate function processing a crafted TIFF file, (2) the png_instantiate function processing a crafted PNG file, and (3) the jpeg_instantiate function processing a crafted JPEG file, all which trigger a heap-based buffer overflow. NOTE: the provenance of this information is unknown; the details are obtained solely from third party information.

rcs2log, as used in Emacs 20.4, xemacs 21.1.10 and other versions before 21.4, and possibly other packages, allows local users to modify files of other users via a symlink attack on a temporary file.