internetnews: More Headaches for Sendmail

“The Sendmail Consortium, which manages deployment of the
world’s most popular message transfer agent (MTA) to handle email,
was left scrambling over the weekend to fix a remotely exploitable
vulnerability that could allow an attacker to gain control of a
unpatched sendmail server.

“The vulnerability, discovered by Michal Zalewski, occurs
because address parsing code in sendmail does not adequately check
the length of email addresses. An email message with a specially
crafted address could trigger a stack overflow. As a result, the
vulnerability can be exploited to cause a denial-of-service
condition and could allow a remote attacker to execute arbitrary
code with the privileges of the sendmail daemon, typically root,
according to a CERT advisory issued over the weekend.

“‘Most organizations have a variety of mail transfer agents
(MTAs) at various locations within their network, with at least one
exposed to the Internet. Since sendmail is the most popular MTA,
most medium-sized to large organizations are likely to have at
least one vulnerable sendmail server. In addition, many UNIX and
Linux workstations provide a sendmail implementation that is
enabled and running by default,’ CERT warned in its
advisory…”

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