From the latest RHN alert: ... A read buffer overflow vulnerability exists in the glibc resolver code in versions of glibc up to and including 2.2.5. The vulnerability is triggered by DNS packets larger than 1024 bytes and can cause applications to crash.

This is potentially a bad one. More information on the CERT Vulnerability Note.

Updates can be downloaded from this page [RHN membership probably required].

Michael Bauer, author of Building Secure Servers with Linux, explains some of the reasons why it's both possible and worthwhile to secure Linux for use as an Internet server platform. [an O'Reilly Network Article]