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R7-0018: OpenBSD isakmpd payload handling denial-of-service vulnerabilities
From: advisory () rapid7 com
Date: Tue, 23 Mar 2004 14:36:54 -0800
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Rapid7, Inc. Security Advisory
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Rapid7 Advisory R7-0018
OpenBSD isakmpd payload handling denial-of-service vulnerabilities
Published: March 23, 2004
CVE: CAN-2004-0218, CAN-2004-0219, CAN-2004-0220, CAN-2004-0221,
1. Affected system(s):
o OpenBSD 3.4 and earlier
o OpenBSD-current as of March 17, 2004
The ISAKMP packet processing functions in OpenBSD's isakmpd
daemon contain multiple payload handling flaws that allow
a remote attacker to launch a denial of service attack
against the daemon.
Carefully crafted ISAKMP packets will cause the isakmpd daemon
to attempt out-of-bounds reads, exhaust available memory, or
loop endlessly (consuming 100% of the CPU).
3. Vendor status and information
OpenBSD has been notified of the issues and they have provided
source code patches to fix the problems for -current, 3.4-stable,
and 3.3-stable. See http://www.openbsd.org/errata.html for
The isakmpd daemon in the upcoming OpenBSD 3.5 release will be
privilege-separated, which greatly lessens the risk of any
future vulnerabilities that may be found.
Update and rebuild the isakmpd daemon:
cvs update -dP
make clean && make obj && make && sudo make install
You can also apply the appropriate patches from
http://www.openbsd.org/errata.html instead of using CVS.
5. Detailed analysis
To test the security and robustness of IPSEC implementations
from multiple vendors, the security research team at Rapid7
has designed the Striker ISAKMP Protocol Test Suite. Striker
is an ISAKMP packet generation tool that automatically produces
and sends invalid and/or atypical ISAKMP packets.
This advisory is the first in a series of vulnerability
disclosures discovered with the Striker test suite. Striker
will be made available to qualified IPSEC vendors. Please
email advisory () rapid7 com for more information on obtaining
OpenBSD's isakmpd daemon performs insufficient validation on
payload lengths and payload field lengths before attempting to
read the fields. This results in out-of-bounds reads in several
Denial of service by 0-length ISAKMP payload
CVE ID: CAN-2004-0218
An ISAKMP packet with a malformed payload having a self-reported
payload length of zero will cause isakmpd to enter an infinite
loop, parsing the same payload over and over again.
This issue is similar to CAN-2003-0989, which affected TCPDUMP.
Denial of service by various malformed ISAKMP IPSEC SA payload
CVE ID: CAN-2004-0219
An ISAKMP packet with a malformed IPSEC SA payload will
cause isakmpd to read out of bounds and crash.
Denial of service by malformed ISAKMP Cert Request payload
CVE ID: CAN-2004-0220
An ISAKMP packet with a malformed Cert Request payload
will cause an integer underflow, resulting in a failed
malloc of a huge amount of memory.
Denial of service by malformed ISAKMP Delete payload
CVE ID: CAN-2004-0221
An ISAKMP packet with a malformed delete payload having
a large number of SPIs will cause isakmpd to read out of
bounds and crash.
Denial of service by various memory leaks
CVE ID: CAN-2004-0222
Various memory leaks in packet processing can be triggered
by a remote attacker until all available memory is exhausted,
resulting in eventual termination of the daemon.
6. Contact Information
Rapid7 Security Advisories
Email: advisory () rapid7 com
Phone: +1 (617) 603-0700
7. Disclaimer and Copyright
Rapid7, LLC is not responsible for the misuse of the information
provided in our security advisories. These advisories are a service
to the professional security community. There are NO WARRANTIES
with regard to this information. Any application or distribution of
this information constitutes acceptance AS IS, at the user's own
risk. This information is subject to change without notice.
This advisory Copyright (C) 2004 Rapid7, LLC. Permission is
hereby granted to redistribute this advisory, providing that no
changes are made and that the copyright notices and disclaimers
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- R7-0018: OpenBSD isakmpd payload handling denial-of-service vulnerabilities advisory (Mar 24)