[11871] in bugtraq
Re: local telnetd DoS
daemon@ATHENA.MIT.EDU (Henrik Nordstrom)
Mon Sep 13 18:15:52 1999
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Message-Id: <37DA1E77.56F073F4@hem.passagen.se>
Date: Sat, 11 Sep 1999 11:18:47 +0200
Reply-To: hno@HEM.PASSAGEN.SE
From: Henrik Nordstrom <hno@HEM.PASSAGEN.SE>
X-To: Zo0mer <slackware@MAIL.RU>
To: BUGTRAQ@SECURITYFOCUS.COM
Zo0mer wrote:
>
> Hi,i found local DoS that Crash telnetd (tested on Slackware 4.0, RH 5.2)
> type
> telnet localhost | telnet localhost | telnet localhost ...... about 50 times
> result will be 'Connection Refused' , telnetd crash.
Sounds very much like inetd service respawn rate limitation. The default
rate limit is usually something like 40 accesses/minute. See your inetd
documentation for exact value of the default limit and how it may be
tuned.
The purpose of this limit is to limit the DOS attack to only the service
attacked and not bring down the whole machine by resource exhaustion
(memory, processes, CPU).
--
Henrik Nordstrom
