Recipe 10.3 Updating to Close Security Holes

Problem

You must close known sendmail security holes that intruders are exploiting.

Solution

Subscribe to the sendmail-announce mailing list to receive notification of important security updates by sending mail to [e-mail] that contains the following line:

 subscribe sendmail-announce 

Download the sendmail source code distribution to fix any known security problems. Detailed instructions for downloading the sendmail distribution are found in Recipe 1.1.

Restore, recompile, and reinstall sendmail as described in Recipe Recipe 1.2.

Discussion

Failure to fix known security problems is the single biggest security threat to all systems. Intruders frequently exploit known security holes to crash systems or gain access ”even root access. Subscribing to sendmail-announce lets you know if there are sendmail security fixes that affect your system. Downloading, compiling, and installing the new version of sendmail is a security priority.

See Also

Recipe 1.1 and Recipe 1.2 cover downloading, compiling, and installing sendmail. Recipe 1.3 to Recipe 1.7 provide additional examples of recompiling sendmail. Chapter 2 of the sendmail book provides extensive details on installing an updated version of sendmail.