Evolution is the integrated collection of e-mail, calendaring, contact management, communications, and personal information management tools for the GNOME desktop environment. It was discovered that evolution did not properly validate NTLM authentication challenge packets. A malicious server using NTLM authentication could cause evolution to disclose portions of its memory or crash during user authentication. An integer overflow flaw which could cause heap-based buffer overflow was found in the Base64 encoding routine used by evolution. This could cause evolution to crash, or, possibly, execute an arbitrary code when large untrusted data blocks were Base64-encoded. All users of evolution are advised to upgrade to these updated packages, which contain backported patches to correct these issues. All running instances of evolution must be restarted for the update to take effect.