While the following advisory specifically mentions sendmail, the problem described may be present in other utilities. Please upgrade as soon as possible.
Systems running old versions of sendmail are a preferred target for intruders.
Although these reports have focused only on DNS, this vulnerability could apply to any network service from which data is received and subsequently used. Section III.A contains a pointer to two subroutines that address the DNS problem. This advisory speaks to a specific instance of a problem caused by the information returned by DNS, but information from any server should be checked for validity. Impact Programs that do not check data provided by information servers may operate in unpredictable ways and give unexpected results. In particular, exploitation of this vulnerability may allow remote access by unauthorized users.