Ludwig Nussel discovered that gnucash contained a script that could be abused by an attacker to execute arbitrary code.

The vulnerability is due to an insecure change to LD_LIBRARY_PATH, and environment variable used by ld.so(8) to look for libraries in directories other than the standard paths.  When there is an empty item in the colon-separated list of directories in LD_LIBRARY_PATH, ld.so(8) treats it as a '.' (current working directory).  If the given script is executed from a directory where a local attacker could write files, there is a chance for exploitation.

In Fedora, /usr/bin/gnc-test-env re-sets LD_LIBRARY_PATH insecurely:

106 (display
107  (adapt-dirsep
108   (get-dir-adder "LD_LIBRARY_PATH" library-dirs "/.libs" path-sep-str))) 

which could result in something like this if called with, say, --library-dir /foo:

LD_LIBRARY_PATH="/foo/.libs:${LD_LIBRARY_PATH}"  export LD_LIBRARY_PATH;

I'm not sure what the best solution here to fix this flaw is, however it looks as though gnc-test-env is only required for building gnucash, so it should probably be removed from the RPM package (it isn't something an end-user would be running normally).