Enhanced tcp_wrappers packages are now available for Red Hat Enterprise Linux 6.
The tcp_wrappers packages provide small daemon programs which can monitor and filter incoming requests for systat, finger, FTP, telnet, rlogin, rsh, exec, tftp, talk and other network services. These packages also contain the libwrap library, which adds the same filtering capabilities to programs linked against it, such as to sshd among others.
Previously, the tcp_wrappers packages were compiled without the RELRO (read-only relocations) flag. Programs provided by this package and also programs built against the tcp_wrappers libraries were thus vulnerable to various attacks based on overwriting the ELF section of a program. To increase the security of tcp_wrappers programs and libraries, the tcp_wrappers spec file has been modified to use the "-Wl,-z,relro" flags when compiling the packages. As a result, the tcp_wrappers packages are now provided with partial RELRO protection.
Users of tcp_wrappers are advised to upgrade to these updated packages, which add this enhancement.