Three issues have been found in the libXpm library code to read XPM files in libXpm 3.5.14 and earlier releases.
When reading XPM images from a file with libXpm 3.5.14 or older, if a comment in the file is not closed (i.e. a C-style comment starts with "/" and is missing the closing "/"), the ParseComment() function will loop forever calling getc() to try to read the rest of the comment, failing to notice that it has returned EOF, which may cause a denial of service to the calling program.
This issue was found by Marco Ivaldi of the Humanativa Group's HN Security team.
When reading XPM images from a file with libXpm 3.5.14 or older, if a image has a width of 0 and a very large height, the ParsePixels() function will loop over the entire height calling getc() and ungetc() repeatedly, or in some circumstances, may loop seemingly forever, which may cause a denial of service to the calling program when given a small crafted XPM file to parse.
This issue was found by Martin Ettl.
By default, on all platforms except MinGW, libXpm will detect if a filename ends in .Z or .gz, and will when reading such a file fork off an uncompress or gunzip command to read from via a pipe, and when writing such a file will fork off a compress or gzip command to write to via a pipe.
In libXpm 3.5.14 or older these are run via execlp(), relying on $PATH to find the commands. If libXpm is called from a program running with raised privileges, such as via setuid, then a malicious user could set $PATH to include programs of their choosing to be run with those privileges.
This issue was found by Alan Coopersmith of the Oracle Solaris team.