The libuser library implements a standardized interface for manipulating and administering user and group accounts. Sample applications that are modeled after applications from the shadow password suite are included in these packages. Two flaws were found in the way the libuser library handled the /etc/passwd file. A local attacker could use an application compiled against libuser to manipulate the /etc/passwd file, which could result in a denial of service or possibly allow the attacker to escalate their privileges to root. Red Hat would like to thank Qualys for reporting these issues. All libuser users are advised to upgrade to these updated packages, which contain a backported patch to correct this issue.