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AUSCERT External Security Bulletin Redistribution
ESB-2012.0066
An Error in DDNS Processing of DHCPv6 Leases Can Cause a Crash in ISC dhcpd
17 January 2012
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AusCERT Security Bulletin Summary
---------------------------------
Product: DHCP
Publisher: Internet Systems Consortium
Operating System: UNIX variants (UNIX, Linux, OSX)
Windows
Impact/Access: Denial of Service -- Remote/Unauthenticated
Resolution: None
CVE Names: CVE-2011-4868
Original Bulletin:
http://www.isc.org/software/dhcp/advisories/cve-2011-4868
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An Error in DDNS Processing of DHCPv6 Leases Can Cause a Crash in ISC dhcpd
Improper handling of Dynamic DNS information associated with DHCPv6 leases can
cause a segmentation fault in ISC DHCP servers using IPv6 and Dynamic DNS,
resulting in denial of service to clients.
CVE: CVE-2011-4868
Document Version: 1.2
Posting date: 12 Jan 2012
Program Impacted: DHCP
Versions affected: 4.2.2, 4.2.3, 4.2.3-P1
Severity: High
Exploitable: remotely
Description:
Due to improper handling of a DHCPv6 lease structure, ISC DHCP servers that
are serving IPv6 address pools AND using Dynamic DNS can encounter a
segmentation fault error while updating lease status under certain conditions.
The potential exists for this condition to be intentionally triggered,
resulting in effective denial of service to clients expecting service from the
affected server. Users of affected versions who use DHCPv6 and Dynamic DNS
should upgrade to version 4.2.3-P2.
CVSS Score: 6.1
CVSS Equation:
For more information on the Common Vulnerability Scoring System and to
obtain your specific environmental score please visit:
http://nvd.nist.gov/cvss.cfm?calculator&adv&version=2&vector=%28AV:A/AC:L/Au:N/C:N/I:N/A:C%29
Workarounds:
No known workarounds, please upgrade if you are running an affected version of
ISC DHCP and you use Dynamic DNS and IPv6. Active exploits: None known at this
time. Solution:
Upgrade to ISC DHCP 4.2.3-P2
DHCP 4.2.3-P2 can be downloaded from the following location:
http://www.isc.org/software/dhcp
Document Revision History:
1.0 05 January 2012 - Phase I notified
1.1 11 January 2012 - Phase II & III notified
1.2 12 January 2012 - Public Release
Related Document:
References:
Do you have Questions? Questions regarding this advisory should go to
security-officer@isc.org. ISC Security Vulnerability Disclosure Policy:
Details of our current security advisory policy and practice can be found
here: https://www.isc.org/security-vulnerability-disclosure-policy
Legal Disclaimer:
Internet Systems Consortium (ISC) is providing this notice on an "AS IS"
basis. No warranty or guarantee of any kind is expressed in this notice and
none should be implied. ISC expressly excludes and disclaims any warranties
regarding this notice or materials referred to in this notice, including,
without limitation, any implied warranty of merchantability, fitness for a
particular purpose, absence of hidden defects, or of non-infringement. Your
use or reliance on this notice or materials referred to in this notice is at
your own risk. ISC may change this notice at any time.
A stand-alone copy or paraphrase of the text of this document that omits the
document URL is an uncontrolled copy. Uncontrolled copies may lack important
information, be out of date, or contain factual errors.
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The University of Queensland
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