An updated passwd package that adds two enhancements is now available for Red Hat Enterprise Linux 6.
The passwd packages contain a system utility, "passwd", which changes passwords and displays password status information using the Pluggable Authentication Modules (PAM) and Libuser libraries.
The passwd command now supports a new option, "-e", that allows the system administrator to expire the password of the specified user so that the user is forced to change the password on the next login attempt.
The passwd executable file is a setuid program so it needs to be well protected against various types of attacks. With this update, passwd has been built with the Position Independent Executables (PIE) flag, "-fPIE -pie", and the full read-only relocations (RELRO) flags, "-Wl,-z,relro,-z,now". The passwd binary is now well protected against "return-to-text" and memory corruption attacks and also against attacks based on the program's ELF section overwriting.
All users of passwd are advised to upgrade to this updated package, which adds these enhancements.