glibc local write access vulnerability

A bug in GNU C Library allows unprivileged user to preload libraries
located in /lib or /usr/lib directories into SUID programs even if those
libraries have not been marked as such by system administrator.

LD_PRELOAD variable is honoured normally even for SUID/SGID applications
(but removed afterwards from environment) if it does not contain `/'
characters, but there is a special check which only preloads found
libraries if they have the SUID bit set. However, if a library has been
found
in /etc/ld.so.cache, this check was not performed. As a result, a
malicious user
could preload some /lib or /usr/lib library before SUID/SGID application
and create or overwrite a file he did not have permissions to.
Also, LD_PROFILE output from SUID programs would go into /var/tmp,
making it vulnerable to various link attacks.