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Vulnerability Assessment Details

SSA-2003-251-01 inetd DoS patched

Vulnerability Assessment Summary
SSA-2003-251-01 inetd DoS patched

Detailed Explanation for this Vulnerability Assessment

Upgraded inetd packages are available for Slackware 8.1, 9.0 and
- -current. These fix a previously hard-coded limit of 256
connections-per-minute, after which the given service is disabled
for ten minutes. A possible hacker could use a quick burst of
connections every ten minutes to effectively disable a service.

Once upon a time, this was an intentional feature of inetd, but in
today's world it has become a bug. Even having inetd look at the
source IP and try to limit only the source of the attack would be
problematic since TCP source addresses are so easily faked. So,
the approach we have taken (borrowed from FreeBSD) is to disable
this rate limiting "feature" by default. It can be reenabled by
providing a -R option on the command-line if desired, but
for obvious reasons we do not recommend this.

Any site running services through inetd that they would like
protected from this simple DoS attack should upgrade to the new
inetd package immediately.

Networks Security ID:

Vulnerability Assessment Copyright: This script is Copyright (C) 2005 Michel Arboi

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