A stack-based buffer overflow was found in systemd-ask-password, a utility used to query a system password or passphrase from the user, using a question message specified on the command line. A local user could this flaw to crash the binary or even execute arbitrary code with the permissions of the user running the program.
This issue is fixed upstream via the following commit:
*** Bug 1085120 has been marked as a duplicate of this bug. ***
systemd-208-16.fc20 has been pushed to the Fedora 20 stable repository. If problems still persist, please make note of it in this bug report.
After investigation it seems that the only impact of this flaw is crash of the "systemd-ask-password" utility. Systemd does not use this utility in anyway which could result in privilege escalation or any other form of exploitation.
The Red Hat Security Reponse Team does not consider this issue to be a security flaw.
Red Hat does not consider a user assisted client crash such as this to be a security flaw. For more details please refer to https://bugzilla.redhat.com/show_bug.cgi?id=1084286#c6