by Please direct any follow-ups to comp.sys.hp.hpux.
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**REVISED 01** HEWLETT-PACKARD SECURITY BULLETIN: #00076, 21 January 1998
Last Revised: 11 February 1998
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The information in the following Security Bulletin should be acted upon
as soon as possible. Hewlett-Packard will not be liable for any
consequences to any customer resulting from customer's failure to fully
implement instructions in this Security Bulletin as soon as possible.
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PROBLEM: A TCP SYN packet with target host's address as both source and
destination can cause system hangs.
PLATFORM: HP9000 Series 7/800 running HP-UX releases 9.X, 10.X, and 11.00.
DAMAGE: Users on the network can cause system hangs.
SOLUTION: Apply patches listed below.
AVAILABILITY: All patches are available now.
CHANGE SUMMARY: Adds patches for HP-UX release 10.24 (VVOS)
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I.
A. Background
CERT Advisory CA-97.28 discusses the widely available "land" program,
a denial of service tool that is effective against HP-UX systems.
land sends carefully crafted TCP packets (the source and destination
are identical).
**REVISED 01**
B. Fixing the problem
The problem can be fixed by applying the appropriate cumulative ARPA
Transport patch mentioned below.
---->>HP-UX release 11.00 HP9000 Series 700/800 PHNE_14017
HP-UX release 10.30 HP9000 Series 700/800 PHNE_13671
HP-UX release 10.20 HP9000 Series 800 PHNE_13468
---->>HP-UX release 10.24 HP9000 Series 700 PHNE_13888
---->>HP-UX release 10.24 HP9000 Series 800 PHNE_13889
HP-UX release 10.20 HP9000 Series 800 PHNE_13468
HP-UX release 10.20 HP9000 Series 700 PHNE_13469
HP-UX release 10.10 HP9000 Series 800 PHNE_13470
HP-UX release 10.10 HP9000 Series 700 PHNE_13471
HP-UX release 10.01 HP9000 Series 800 PHNE_13472
HP-UX release 10.01 HP9000 Series 700 PHNE_13473
HP-UX release 10.00 HP9000 Series 800 PHNE_13474
HP-UX release 10.00 HP9000 Series 700 PHNE_13475
HP-UX release 9.04 HP9000 Series 800 PHNE_13476
HP-UX release 9.0[3,5,7] HP9000 Series 700 PHNE_13477
HP-UX release 9.01 HP9000 Series 700 PHNE_13478
HP-UX release 9.00 HP9000 Series 800 PHNE_13479
C. Impact of the patch
The patch changes the implementation of the ISO OSI stack such
that the host now enforces the rule that inbound packets are never
from itself - if packets claim otherwise, they are simply dropped.
D. To subscribe to automatically receive future NEW HP Security
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Click on the Technical Knowledge Database, register as a user
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Near the bottom is a hyperlink to our Security Bulletin archive.
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F. To report new security vulnerabilities, send email to
Please encrypt any exploit information using the security-alert
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