The mkdir procedure of GNU Guile, an implementation of the Scheme programming language, temporarily changed the process' umask to zero. During that time window, in a multithreaded application, other threads could end up creating files with insecure permissions. For example, mkdir without the optional mode argument would create directories as 0777.
Created compat-guile18 tracking bugs for this issue:
Affects: fedora-all [bug 1383974]
Affects: epel-7 [bug 1383975]
Created guile tracking bugs for this issue:
Affects: fedora-all [bug 1383973]
The opportunity for impact here is quite small, requiring mkdir-with-mask to be executed simultaneously with either mkdir-without-mask or create-file-without-mask in another thread. The impact is for a directory or file to be created with too-permissive permissions, so that another local user might be able to read or write to it - subject to permissions of its containing directory.
Red Hat Product Security has rated this issue as having Low security
impact. This issue is not currently planned to be addressed in future
updates. For additional information, refer to the Issue Severity