ircd-hybrid/ircd-ratbox: multiple vulnerabilities

David Leadbeater discovered an integer underflow that could be triggered via the LINKS command and can lead to a denial of service or the execution of arbitrary code (CVE-2009-4016). This issue affects both, ircd-hybrid and ircd-ratbox.

It was discovered that the ratbox IRC server is prone to a denial of service attack via the HELP command. The ircd-hybrid package is not vulnerable to this issue (CVE-2010-0300).